Effects of short-term motor training on accuracy and precision of simple jaw and finger movements after orthodontic treatment and orthognathic surgery: A case-control study.

BACKGROUND: Orthognathic surgery has been performed with increasing frequency for the treatment of severe malocclusion, yet the postsurgical neuromuscular recovery of patients has been inadequately studied. OBJECTIVE: To investigate the effect of short-term and simple jaw motor training on accuracy and precision of jaw motor control in patients following orthodontic treatment and orthognathic surgery. METHODS: Twenty patients who had completed preoperative orthodontics, 20 patients who had undergone bimaxillary orthognathic surgery and 20 age-and-gender-matched healthy controls participated in the study. Participants were asked to perform 10 continuous jaw opening and finger lifting movements before and after a 30-min motor training session. The variability in the amplitude of these simple movements was expressed as percentage in relation to the target position (accuracy - Daccu ) and as coefficient of variation (precision - CVprec ) to describe the motor performance. Furthermore, the changes in amplitude before and after training were measured in percentage. RESULTS: Daccu and CVprec of simple jaw and finger movements significantly decreased after motor training (p ≤ .018) in all groups. The relative changes in finger movements were higher than jaw movements (p < .001) but with no differences among the groups (p ≥ .247). CONCLUSION: Both accuracy and precision of simple jaw and finger movements improved after short-term motor training in all three groups, demonstrating the inherent potential for optimization of novel motor tasks. Finger movements improved more than jaw movements but with no differences between groups, suggesting that changes in occlusion and craniofacial morphology are not associated with impaired neuroplasticity or physiological adaptability of jaw motor function.

Uptight responses between clenching and forearm raising with factors of visual feedback and maintenance effort in healthy young women: An experimental study on factorial design.

BACKGROUND: To achieve different central preset force levels requires various fine-tuning efforts and may elicit different uptight responses. The mandibular lever system has a distinct regularity in the fine-tuning function of the upper limbs. The purpose of the present study was to detect whether the uptight responses elicited from motivating clenching differ from those induced by motivating forearm raising at different force levels. METHODS: Twenty-five healthy females were enrolled in this study. The target was low, medium, and maximum force levels with or without visual feedback and/or maintenance effort. Surface electromyographic (SEMG) activity was recorded from the bilateral anterior temporalis and masseter or left biceps brachii muscle (BicL), and the T-Scan III System synchronously recorded the sensitive force values. The uptight responses and task difficulties were recorded for occlusal and left forearm lifting tasks using a unique visual analogue scale. RESULTS: The highest uptight response value was achieved at a low clenching force level with visual feedback requiring no maintenance effort but at a maximum forearm-raising force level with visual feedback and maintenance effort. The SEMG activities of both jaw-closing muscles and BicL were associated with the central preset force level (P < 0.001). However, the maintenance effort only increased the jaw-closing muscles' SEMG activity at the maximal force level (P < 0.001). CONCLUSIONS: Clenching at the central preset lower force level with visual feedback is prone to elicit a higher degree of uptight response. The constant need for a low-intensity bite can have a negative effect on an individual's mood.

Conditioned pain modulation is not associated with thermal pain illusion.

OBJECTIVES: Paradoxical sensations, known as thermal pain illusions, can be evoked by painful cold-heat pulse stimulation. They may provide diagnostic value; however, the possible interaction between conditioned pain modulation and thermal pain illusions has not been explored. The present study examined: (1) whether conditioned pain modulation could be induced by alternating tonic painful cold-heat pulse stimulation; and (2) whether the presence of thermal pain illusions during the conditioning stimulus influences the degree of conditioned pain modulation. METHODS: This study was approved by the Ethics Committee of Meikai University (A1507). Conditioned pain modulation was provoked using alternating painful cold-heat pulses delivered at 20-s intervals applied to the forearm. Thermal pain illusions were qualitatively evaluated, and conditioned pain modulation was assessed quantitatively using the pressure pain threshold as a test stimulus. Differences in the conditioned pain modulation effect between the participants who experienced thermal pain illusions and those who did not were analysed using Student's t-test. RESULTS: A significant positive conditioned pain modulation effect (51.0 ± 4.7%, overall effect) was detected. There was no significant difference in conditioned pain modulation between the participants who experienced thermal pain illusions and those who did not (44.3 ± 6.0% and 55.5 ± 6.8%, respectively; p = 0.255). CONCLUSIONS: Conditioned pain modulation induced by alternating painful conditioning cold-heat pulse stimulation was identical during the conditioning stimulation in volunteers with and without thermal pain illusions. Conditioning cold-heat pulse stimulation is useful to evaluate conditioned pain modulation. Moreover, conditioned pain modulation is not influenced by the presence of thermal pain illusions, indicating partially different underlying supraspinal, neuronal networks.

Acupuncture for menstruation-related migraine prophylaxis: A multicenter randomized controlled trial.

Objective: The aim of this study was to evaluate the efficacy of acupuncture, an alternative medicine therapy, as a preventive treatment for menstruation-related migraine (MRM). Patients and methods: This was a prospective, multicenter, double-dummy, participant-blinded, randomized controlled clinical trial conducted in China between 1 April 2013, and 30 April 2014. The participants were enrolled from four study centers and randomized to into either the acupuncture group, which received 24 sessions of acupuncture at traditional acupoints plus placebo, or the medication group, which received sham acupuncture plus naproxen. The primary endpoint was change from the baseline average number of migraine days per perimenstrual period over cycles 1-3. The secondary endpoints included changes from the baseline average number of migraine days outside the perimenstrual period, mean number of migraine hours during and outside the perimenstrual period, mean visual analog scale score during and outside the perimenstrual period, ≥50% migraine responder rate, and the proportion of participants who used acute pain medication over cycles 1-3 and 4-6. Results: A total of 172 women with MRM were enrolled; 170 in the intention-to-treat analyses. Our primary outcome reported a significant between-group difference that favored the acupuncture group (95% CI, 0.17-0.50; P < 0.001), with the average reduction of migraine days per perimenstrual period from the baseline was 0.94 (95% CI, 0.82-1.07) in the acupuncture group and 0.61 (95% CI, 0.50-0.71) in the medication group over cycles 1-3. Conclusion: This study showed that compared to medication, acupuncture reduces the number of migraine days experienced by patients with MRM. For patients who received the acupuncture treatment over three cycles, the preventive effect of the therapy was sustained for six cycles. Clinical trial registration: [https://www.isrctn.com/ISRCTN57133712], identifier [ISRCTN15663606].

Acute postoperative pain after orthognathic surgery can be predicted by the preoperative evaluation of conditioned pain modulation and pain catastrophizing.

INTRODUCTION: The incidence and severity of chronic postoperative pain (POP) are major clinical challenges, and presurgical conditioned pain modulation (CPM) and pain catastrophizing scale (PCS) assessments have exhibited predictive values for POP. However, whether CPM and PCS assessments are also predictive of acute POP is unknown. OBJECTIVES: We aimed to investigate the relationship between preoperative CPM and PCS and acute POP severity after orthognathic surgery by assessing preoperative CPM and PCS in 43 patients. METHODS: The pressure pain threshold and tonic painful cold-heat pulse stimulation (applied with a pain intensity score of 70 on a visual analogue scale [VAS 0-100]) were used as the test and conditioning stimuli, respectively. The pain area under the postoperative VAS area under the curve (VASAUC) was estimated. The associations between CPM, PCS, and VASAUC were also analyzed. RESULTS: No patient experienced chronic POP after 1 month. Negative and positive CPM effects (test stimulus threshold was 0% > and 0% ≤ during conditioning stimulation, respectively) were detected in 36 and 7 patients, respectively. For patients with negative CPM effects (CPM responders), multiple regression analysis revealed a prediction formula of log (VASAUC) = (-0.02 × CPM effect) + (0.13 × PCS-magnification) + 5.10 (adjusted R 2 = 0.4578, P = 0.00002, CPM effect; P = 0.002, PCS-magnification; P = 0.0004), indicating that a weaker CPM and higher PCS scores were associated with more acute POP after surgery. CONCLUSION: CPM and PCS can predict acute POP after orthognathic surgery.

Quantitative sensory testing of mandibular somatosensory function following orthognathic surgery-A pilot study in Chinese with class III malocclusion.

BACKGROUND: Somatosensory changes after sagittal split ramus osteotomy (SSRO) have not been fully studied in Chinese patients by the latest technologies. OBJECTIVE: To provide a comprehensive analysis of somatosensory function at the lower lip and chin at different time points following SSRO in a Chinese population. METHODS: A total of 22 patients (18-27 years; nine men) with skeletal III malocclusion and scheduled for SSRO were recruited. Quantitative sensory testing (QST) was performed at pre-operation (baseline), 1 week (1W), 1, 3 and 6 months (1M, 3M, 6M) post-operatively. Cold detection threshold (CDT), warm detection threshold (WDT), cold pain threshold (CPT), heat pain threshold (HPT), mechanical detection threshold (MDT), mechanical pain threshold (MPT), pressure pain threshold (PPT) and two-point discrimination threshold (2PD) were tested at the lower lip and chin. RESULTS: Except for PPT at both test sides at 1W and 1M, all QST values indicated a significantly reduced sensitivity (p < .05). All values had returned to baseline values at 3M with exception of HPT at the right chin which, however, had recovered at 6M (p > .05). CONCLUSIONS: Somatosensory function at the lower lip and chin appears to be fully recovered in the majority of young Chinese adults 6 months after SSRO for skeletal class III malocclusion.

Painful cold-heat segmental pulse stimulation provokes the thermal pain illusion.

PURPOSE/AIM: The thermal grill illusion is a paradoxical pain sensation induced by simultaneous exposure to spatially separated, non-painful, cold, and warm stimuli. This study aimed to determine whether paradoxical sensations are also evoked by simultaneous exposure to painful cold-heat stimuli and whether the mechanism involves modulation by segmental and extra-segmental spatial integration. MATERIALS AND METHODS: Sensory perceptions were triggered by simultaneous application of painful cold-heat pulse stimuli using a developed bedside tool equipped with quantitative thermal stimulator devices. Four conditions were investigated: (1) one device placed on the forearm (condition 1, control); (2) two devices placed on the forearm (condition 2, ipsilateral segmental integration); (3) two devices placed on the forearm and ipsilateral thigh (condition 3, extra-segmental integration); and (4) two devices placed bilaterally on the forearms (condition 4, contralateral segmental integration). The evoked perceptions of paradoxical heat sensation and the loss of cold or heat sensation were evaluated. RESULTS: The aforementioned phenomena were experienced by 11(35.4%), 3(9.7%), 3(9.7%), and 0(0.0%) subjects for conditions 1-4, respectively. Fisher's exact test revealed significant differences (p=.001) among the four conditions. However, Bonferroni post hoc analysis revealed significant differences only between conditions 1 and 4 (p=.005). CONCLUSIONS: Simultaneous painful cold-heat pulse stimulation can induce paradoxical sensations similar to those shown for non-painful thermal (cold and heat) stimuli. They were predominantly evoked by ipsilateral integration. Paradoxical sensations have diagnostic value, and quantifying them using a simple bedside tool may be useful in the clinical setting.

Corrigendum to "Effects of Motor Training on Accuracy and Precision of Jaw and Finger Movements".

[This corrects the article DOI: 10.1155/2019/9593464.].

Sensory recovery and oral health-related quality of life following tongue reconstruction using non-innervated radial forearm free flaps.

OBJECTIVES: This study aimed to monitor the recovery of somatosensory function and oral health-related quality of life after tongue reconstruction using a non-innervated radial forearm free flap (RFFF). METHODS: Twenty patients (9 men, age: 42-67 years) underwent tongue reconstruction with non-innervated RFFFs, and twenty age- and sex-matched controls were included in this study. Quantitative sensory testing (QST), including cold, warm, and mechanical detection thresholds (CDT, WDT, MDT); cold, heat, and mechanical pain thresholds (CPT, HPT, MPT); and static two-point, sharp/blunt, and direction discrimination (S2-PD, S/BD, DD) were determined 9 months and 18 months after surgery on the surgical (9 M, 18 M) and contralateral sides (9Mc, 18Mc). Oral Health Impact Profile-49 (OHIP-49) was used to determine the oral-related quality of life of participants. RESULTS: All parameters showed significantly lower sensitivity at 9 M and 18 M (p < 0.001) compared to those for the controls and the contralateral side, except for DD (p = 0.101). In addition, the parameters showed a significant decrease in sensitivity for 9Mc and 18Mc (p ≤ 0.043) compared to those for the controls, except for MPT, HPT, S/SD, and DD (p ≥ 0.453). Findings on WDT, MPT, S2-PD, and DD (p ≤ 0.046) indicated significantly higher somatosensory function at 18 M than that at 9 M. MDT and MPT (p ≤ 0.038) showed significantly higher sensitivity at 18Mc than at 9Mc. Scores for all dimensions of OHIP-49 were significantly higher in patients (decrease in quality of life, p ≤ 0.002) than in controls, except for physical discomfort (p = 0.51). However, the scores were significantly higher at 18 M than at 9 M (p ≤ 0.011), except for handicap (p = 0.36). Postoperative chemotherapy was significantly correlated with impaired thermal sensitivity of the flaps (WDT, p = 0.049). CONCLUSION: The present findings showed significant impairment in somatosensory function on both the surgical and contralateral sides of patients with RFFFs. However, a significant increase in somatosensory function was observed on both sides over time. Somatosensory disturbances observed after surgery were associated with poor oral health-related quality of life.

Dentists have a high occupational risk of neck disorders with impact on somatosensory function and neck mobility.

OBJECTIVES: Musculoskeletal disorders (MSDs) in the neck and shoulder region may be associated with significant impairment of quality of life and well-being. The study was to determine the prevalence of painful MSDs in Chinese dentists and evaluate somatosensory function and neck mobility compared with non-dental professional controls. METHODS: One hundred dentists (age: 36.5 ± 9.8 years) and 102 controls (age: 36.2 ± 10.0 years) were recruited between September 2019 and December 2020. The Medical Outcome Study 36-item short-form health survey questionnaire and information of MSDs history were recorded. The cervical range of motion (CROM) with and without pain, and the pressure pain thresholds (PPTs) of the facial and neck muscles were tested. Chi-square test, Mann-Whitney U test and multiple linear regression analysis were used to analyze the data. The factors in the multiple linear regression analysis were occupation, working age, and gender. RESULTS: The prevalence rate of neck pain was significantly higher in dentists (73.0%) compared with the controls (52.0%) (P = .002). The regression models of cervical range of posterior extension, lateral flexion and rotation were statistically significant (P ≤ .001). The regression models of PPTs of the tested facial and neck muscles were statistically significant (P < .001). CONCLUSION: Dentists are at higher risk of neck pain. The bigger cervical range of left rotation of dentists could be related to the working posture. The lower PPTs in dentists may reflect a hypersensitivity in the facial and neck muscles. Preventive measures are needed to reduce occupational hazards in dentists.

Effect of photobiomodulation therapy on painful temporomandibular disorders.

To evaluate the effect of photobiomodulation therapy (PBMT) on painful temporomandibular disorders (TMD) patients in a randomized, double-blinded, placebo-controlled manner. Participants were divided into a masseter myalgia group (n = 88) and a temporomandibular joint (TMJ) arthralgia group (n = 87) according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Both groups randomly received PBMT or placebo treatment once a day for 7 consecutive days, one session. The PBMT was applied with a gallium-aluminum-arsenide (GaAlAs) laser (wavelength = 810 nm) at pre-determined points in the masseter muscle (6 J/cm2, 3 regions, 60 s) or TMJ region (6 J/cm2, 5 points, 30 s) according to their most painful site. Pain intensity was rated on a 0-10 numerical rating scale (NRS) and pressure pain thresholds (PPT) and mechanical sensitivity mapping were recorded before and after the treatment on day 1 and day 7. Jaw function was assessed by pain free jaw opening, maximum unassisted jaw opening, maximum assisted jaw opening, maximum protrusion and right and left excursion. Data were analyzed with a mixed model analysis of variance (ANOVA). Pain intensity in arthralgia patients decreased over time (P < 0.001) for both types of interventions, however, PBMT caused greater reduction in pain scores than placebo (P = 0.014). For myalgia patients, pain intensity decreased over time (P < 0.001) but without difference between interventions (P = 0.074). PPTs increased in both myalgia (P < 0.001) and TMJ arthralgia patients over time (P < 0.001) but without difference between interventions (P ≥ 0.614). Overall, PBMT was associated with marginally better improvements in range of motion compared to placebo in both myalgia and arthralgia patients. Pain intensity, sensory function and jaw movements improve after both PBMT and placebo treatments in myalgia and arthralgia patients indicating a substantial non-specific effect of PBMT.

Effects of Novel Vibro-Acupuncture on Healthy Subjects and Those with Experimental and Clinical Pain as Assessed by Quantitative Sensory Testing.

Background: To investigate the analgesic effects of vibro-acupuncture (VA), a novel acuvibrator was developed. Objectives: To compare the analgesic effects of VA with those of manual acupuncture (MA) and placebo acupuncture (PA) on subjects with normal sensory perception (Study I), experimentally induced acute pain (Study II), and clinical chronic pain (Study III). Methods: Thirty healthy volunteers (21 males, age: 20-30 years) participated in Study I. Fourteen healthy volunteers (8 males, age: 20-32 years) participated in Study II in which experimental pain was induced by injection of hypertonic saline. Fourteen patients suffering from unilateral epicondylalgia (9 males, age: 30-61 years) participated in Study III. All participants received VA, MA, and PA at LI4 and LI10 points in a randomized, crossover, and double-blinded manner. Quantitative sensory testing (QST) was performed on the ipsilateral forearm before and after each treatment. Data were analyzed using repeated-measures (RM) ANOVA. Results: A significantly higher vibration detection threshold (VDT) was observed after treatment of VA than after MA and PA (p < 0.001). No significant treatment effect on experimental pain intensity was detected (p > 0.086). Significantly lower pain intensity (p = 0.005) and a smaller drawing area (p = 0.011) of unilateral epicondylalgia were found after VA treatment than after PA. Conclusion: A specific effect on the VDT beyond that of MA and PA was evoked by VA. Patients with epicondylitis showed significantly lower pain intensity during VA than during PA. This study indicated that VA may be beneficial in individuals with clinical chronic musculoskeletal pain; however, further studies are needed.

Microcirculation and somatosensory profiling of patients with periodontitis: a preliminary case control report.

OBJECTIVES: The purpose of this preliminary study was to explore blood microcirculation and somatosensory profiles in periodontitis patients before and after non-surgical periodontal therapy. MATERIALS AND METHODS: Twenty patients (10 men and 10 women, 20 to 30 years old) and 20 age- and gender-matched healthy controls were included. Non-surgical periodontal therapy was performed for all patients. Clinical examination including pocket probing depth (PPD), clinical attachment loss (CAL), and bleeding on probing (BOP) were performed at baseline (BL), 1 week (1W), and 4 weeks (4W) after non-surgical periodontal therapy on 6 sites of tooth 32 and 42. Laser Doppler flowmetry (LDF) and quantitative sensory testing (QST) were applied at the attached gingiva of tooth 32 and 42 at BL, 1W, and 4W after non-surgical periodontal therapy. Data were analyzed with a two-way mixed-model of ANOVA. RESULTS: The PPD, CAL and BOP significantly improved after non-surgical periodontal therapy (p < 0.001). Periodontitis patients demonstrated a higher tissue microvascular blood cell concentration (p = 0.015) and a significant gain in thermal (p = 0.037) and mechanical (p = 0.003) somatosensory function compared to controls. After non-surgical periodontal therapy, the flux (p = 0.002) and speed (p = 0.008) of blood flow decreased significantly and thermal (p = 0.029) and mechanical (p < 0.001) somatosensory function were reversed. CONCLUSION: Gingival microcirculation and somatosensory function seem impaired in patients with periodontitis and are reversed following non-surgical periodontal therapy. CLINICAL RELEVANCE: LDF and QST may be appropriate tools to further characterize gingival inflammation and treatment responses in periodontitis.

Quantitative sensory testing of periauricular skin in healthy adults.

The aim of this study was to investigate the test-retest reliability of quantitative sensory testing (QST) and mechanical sensitivity mapping of the periauricular skin. Twenty volunteers (10 men, 10 women) participated in two sessions at intervals of one week. Cold and warm detection threshold (CDT&WDT), cold and heat pain threshold (CPT&HPT), mechanical detection and pain threshold (MDT&MPT), pressure pain threshold (PPT) and two-point discrimination (2PD) were measured at five sites: bilateral subauricular and postauricular sites (LA, RA, LB, RB) and the dorsum of left hand (control). Pressure stimulation was applied at each of the four periauricular test sites. The test-retest reliability of the QST data implied fair to excellent agreement as evaluated by the intra-class correlation coefficients (ICC; all >0.4) for different days. There was no difference between each side in the QST parameters and mechanical sensitivity mapping (P ≥ 0.057). Significant differences between subauricular and postauricular sites were shown for WDT and PPT (P ≤ 0.028). NRS scores of mechanical sensitivity mapping showed significant effects of gender, site and point (P ≤ 0.040). QST and mechanical sensitivity mapping can be considered to be a reliable technique to assess somatosensory function of the periauricular skin.

Adjunctive effects of laser therapy on somatosensory function and vasomotor regulation of periodontal tissues in patients with periodontitis: A randomized controlled clinical trial.

BACKGROUND: The purpose of this prospective study was to compare the changes in periodontal somatosensory function and microcirculation in patients with periodontitis following initial treatment with scaling and root planing (SRP) with or without adjuvant laser therapy. METHODS: Twenty-four patients suffering from periodontitis were recruited and randomly allocated into a split-mouth design to either SRP combined laser therapy side (test side) or SRP only side (control side). All treatments were performed by the same investigator at a single visit. Laser Doppler Flowmetry (LDF) and Quantitative Sensory Testing (QST) were performed at baseline (W0), 1 week (1W), 2 weeks (2W), and 4 weeks (4W) after treatment on both sides of the attached gingiva of the maxillary lateral incisor. Clinical examination including probing depth (PD) and bleeding on probing (BOP) was performed at W0, 2W, and 4W on both sides. Data were analyzed with two-way analysis of variance. RESULTS: PD and BOP significantly improved after treatment (P <0.001). LDF values were significantly decreased on both sides at all follow-up time points (P <0.001), temperature was increased only on the test side (P = 0.017) whereas there was no significant change on the control side (P = 0.792). Significantly less sensitivity was observed for all QST parameters (P <0.030) except for warmth detection after treatment. CONCLUSION: Adjunctive use of laser therapy did not provide any significant clinical advantage or additional effects on the recovery of periodontal somatosensory function or gingival microcirculation in the present study.

Variables associated with use of symptomatic medication during a headache attack in individuals with tension-type headache: a European study.

BACKGROUND: Pharmacological treatment of patients with tension-type headache (TTH) includes symptomatic (acute) and prophylactic (preventive) medication. No previous study has investigated variables associated to symptomatic medication intake in TTH. Our aim was to assess the association of clinical, psychological and neurophysiological outcomes with the use and timing of the use of symptomatic medication in TTH. METHODS: A longitudinal observational study was conducted. One hundred and sixty-eight (n = 168) patients with TTH participated. Pain features of the headache (intensity, frequency, duration), burden of headache (Headache Disability Inventory), sleep quality (Pittsburgh Sleep Quality Index), anxiety/depression (Hospital Anxiety and Depression Scale), trait/state anxiety levels (State-Trait Anxiety Inventory), and bilateral pressure pain thresholds on the temporalis, C5-C6 joint, second metacarpal and tibialis anterior were assessed. Symptomatic medication intake was also collected for a 6-months follow-up period. Differences between patients using or not using symptomatic medication, depending on self-perceived effectiveness, and time (early during an attack, i.e., the first 5 min, or when headache attack is intense) when the symptomatic medication was taken were calculated. RESULTS: One hundred and thirty-six (n = 136, 80%) reported symptomatic medication intake for headache (73% NSAIDs). Sixteen (12%) reported no pain relief, 81 (59%) experienced moderate relief and 39 (29%) total pain relief. Fifty-eight (43%) took 'early medication' whereas 78 (57%) took 'late medication'. Patients taking symptomatic medication in general showed lower headache frequency and lower depressive levels than those patients not taking medication. Symptomatic medication was more effective in patients with lower headache history, frequency, and duration, and lower emotional burden. No differences in pressure pain sensitivity were found depending on the self-perceived effectiveness of medication. Patients taking 'late symptomatic' medication exhibited more widespread pressure pain sensitivity than those taking 'early medication'. CONCLUSIONS: This study found that the effectiveness of symptomatic medication was associated with better headache parameters (history, frequency, or duration) and lower emotional burden. Further, consuming early symptomatic medication at the beginning of a headache attack (the first 5 min) could limit widespread pressure pain sensitivity.

Somatosensory profiling of patients with plaque-induced gingivitis: a case-control study.

OBJECTIVES: This study aimed to assess the mechanical and thermal sensory thresholds of the gingiva in patients with plaque-induced gingivitis compared with a control group to help characterize effects of an inflammatory condition in the oral mucosa on somatosensory function. MATERIALS AND METHODS: Quantitative sensory testing (QST) was used in 22 patients (men 10, women 12, age 20-30 years) with plaque-induced gingivitis at the lower lateral incisors and in 22 age- and gender-matched healthy volunteers as a control group. One lower lateral incisor (32 or 42) was randomly identified for each included subject. Cold detection threshold (CDT), warm detection threshold (WDT), cold pain threshold (CPT), and heat pain threshold (HPT) of the attached gingiva at the identified lower lateral incisors were assessed in both groups. Pressure pain threshold (PPT) at the teeth was also tested from vertical and lateral directions and analyzed. One-way ANOVA was used to compare the mean values of the identified lower lateral incisors between the two groups. RESULTS: The results showed that the CDT (P = 0.027), WDT (P = 0.021), and HPT (P = 0.005) at the gingiva and PPT (P < 0.001) at the identified lower lateral incisors from the vertical direction were significantly less sensitive, whereas the PPT (P = 0.016) at the gingiva of the identified lateral incisors were significantly more sensitive in the gingivitis group compared to the control group. Plaque-induced gingivitis and the inflammatory response appear to be associated with significant changes in somatosensory sensitivity at the gingiva and periodontal tissue in a bidirectional mode, i.e., both increased and decreased sensitivity to different types of stimuli. CONCLUSIONS: Inflammatory reactions in the gingiva seem to be associated with demonstrable changes in somatosensory function including both hypo- and hyperesthesia. CLINICAL RELEVANCE: These findings may have significance for general oral health and well-being in patients with even plaque-induced gingivitis.

Changes in heart rate related to rhythmic masticatory muscle activities and limb movements in patients with sleep bruxism.

Most sleep bruxism (SB) episodes are accompanied by an increase in sympathetic tone and heart rate (HR). To characterise heart rate (HR) changes in relation to rhythmic masticatory muscle activities (RMMAs) in SB patients, polysomnographic recordings were performed on 10 SB patients and 11 normal controls. The duration of movement events, amplitude and duration of HR increases, and time to reach HR peak associated with RMMAs and limb movements (LMs) were determined, and the relationships of the parameters of HR increases with types of movements and RMMAs were analysed. All of the parameters of HR increases associated with three types of movements (RMMAs, RMMAs + LMs and LMs) and masseter activities (phasic, tonic and mixed) were significantly different (two-way ANOVA, P < .001 for all) in both SB patients and controls. The duration of RMMAs/LMs was positively correlated with the parameters (SB patients: R2  = .24-.85, P < .0001; controls: R2  = .23-.68, P < .0001). The amplitude of HR increases was also positively correlated with respiration changes in the SB patients (R2  = .3258, P < .0001) and controls (R2  = .09469, P < .05). The proportions of phasic RMMAs associated with awakenings, microarousals and no cortical arousals were significantly different and so were the proportions of tonic and mixed RMMAs (Friedman's tests, P < .05-.001). The HR increases associated with RMMAs may be intrinsic to the cortical arousal response and autonomic activation, and differences in HR increases associated with different types of movements and RMMAs might be related to the changes in respiration and differences in cortical arousal levels.

Gender differences in clinical and psychological variables associated with the burden of headache in tension-type headache.

Our aim was to assess gender differences in variables associated with the emotional and physical burdens of tension-type headache (TTH). Participants with TTH diagnosed according to the ICHD-III were recruited from three university-based hospitals (in Spain, Italy, Denmark) between January 2015 and June 2017. The physical/emotional headache burden was assessed with the Headache Disability Inventory (HDI-P/HDI-E, respectively). Headache features were collected with a four-week diary. Sleep quality was assessed with Pittsburgh Sleep Quality Index. The Hospital Anxiety and Depression Scale evaluated anxiety and depressive symptom levels. Trait and state anxiety levels were evaluated with the State-Trait Anxiety Inventory. Two hundred and twelve (28% men) participants (aged 41-48 years old) participated. Multiple regression models revealed that sleep quality explained 36.7% of the variance of HDI-E and 31.1% of the variance of HDI-P in men, whereas headache intensity, depressive levels, and younger age explained 37.5% of the variance of HDI-E and 32.8% of the variance of HDI-P in women (all p < .001). This study observed gender differences in variables associated with headache burden in TTH. Management of men with TTH should focus on interventions targeting sleep quality, whereas the management of women with TTH should combine psychological approaches and interventions targeting pain mechanisms.

Effect of transcutaneous electrical nerve stimulation on jaw movement-evoked pain in patients with TMJ disc displacement without reduction and healthy controls.

Objective: Transcutaneous electrical nerve stimulation (TENS) may serve as non-invasive intervention for painful temporomandibular disorders (TMD) to improve jaw motor function, but its efficacy is still debated. This parallel study evaluated the effect of TENS on pain and movement patterns after repeated jaw movements in patients with painful temporomandibular joints (TMJ) and disc displacement without reduction (DDwoR), and compared with healthy controls.Material and Methods: 20 patients with TMJ pain and DDwoR and 20 age- and gender-matched healthy volunteers were randomly assigned to TENS/sham TENS (sTENS) intervention groups in a block design (10 in each group). Participants performed 20 repeated jaw movements (4 x 5 sessions), and reported pain intensity on a 0-10 Numerical Rating Scale (NRS) subsequently both before and after the intervention. Data were tested by repeated measures analysis of variance (ANOVA).Results: Significant increase of pain intensity and reduction of opening range were shown within repeated jaw movements in TMJ pain patients in contrast to healthy participants (p ≤ .001). Pain was significantly reduced during repeated open-close (p = .007), fast open-close (p = .016) and horizontal movements (p = .023), accompanied with increased opening range (p = .033) and open-close velocity (p = .019) with TENS intervention when compared with sTENS group (p > .05) in TMJ pain patients.Conclusions: This study indicated that movement-evoked pain was reduced either spontaneously or by sTENS in TMJ pain patients with DDwoR, and interestingly, that TENS could attenuate movement-evoked pain and improve jaw motor function during repeated jaw movements. The findings may have implications for TENS treatment in TMJ pain patients with DDwoR.