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.

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.

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.

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

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

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.

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.

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.

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.

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

Objective: To compare the effects of training of jaw and finger movements with and without visual feedback on precision and accuracy. Method: Twenty healthy participants (10 men and 10 women; mean age 24.6 ± 0.8 years) performed two tasks: a jaw open-close movement and a finger lifting task with and without visual feedback before and after 3-day training. Individually determined target positions for the jaw corresponded to 50% of the maximal jaw opening position, and a fixed target position of 20 mm was set for the finger. Movements were repeated 10 times each. The variability in the amplitude of the movements was expressed as percentage in relation to the target position (D accu-accuracy) and as coefficient of variation (CVprec-precision). Result: D accu and CVprec were significantly influenced by visual feedback (P = 0.001 and P < 0.001, respectively) and reduced after training jaw and finger movements (P < 0.001). D accu (P = 0.004) and CVprec (P = 0.019) were significantly different between jaw and finger movements. The relative changes in D accu (P = 0.017) and CVprec (P = 0.027) were different from pretraining to posttraining between jaw and finger movements. Conclusion: The accuracy and precision of standardized jaw and finger movements are dependent on visual feedback and appears to improve more by training in the trigeminal system possibly reflecting significant neuroplasticity in motor control mechanisms.

An updated review on pathophysiology and management of burning mouth syndrome with endocrinological, psychological and neuropathic perspectives.

Burning mouth syndrome (BMS) is a chronic oro-facial pain disorder of unknown cause. It is more common in peri- and post-menopausal women, and sex hormone dysregulation is believed to be an important causative factor. Psychosocial events often trigger or exacerbate symptoms, and persons with BMS appear to be predisposed towards anxiety and depression. Atrophy of small nerve fibres in the tongue epithelium has been reported, and potential neuropathic mechanisms for BMS are now widely investigated. Historically, BMS was thought to comprise endocrinological, psychosocial and neuropathic components. Neuroprotective steroids and glial cell line-derived neurotrophic factor family ligands may have pivotal roles in the peripheral mechanisms associated with atrophy of small nerve fibres. Denervation of chorda tympani nerve fibres that innervate fungiform buds leads to alternative trigeminal innervation, which results in dysgeusia and burning pain when eating hot foods. With regard to the central mechanism of BMS, depletion of neuroprotective steroids alters the brain network-related mood and pain modulation. Peripheral mechanistic studies support the use of topical clonazepam and capsaicin for the management of BMS, and some evidence supports the use of cognitive behavioural therapy. Hormone replacement therapy may address the causes of BMS, although adverse effects prevent its use as a first-line treatment. Selective serotonin reuptake inhibitors (SSRIs) and serotonin and noradrenaline reuptake inhibitors (SNRIs) may have important benefits, and well-designed controlled studies are expected. Other treatment options to be investigated include brain stimulation and TSPO (translocator protein 18 kDa) ligands.

Characterisation of the relationships between rhythmic masticatory muscle activities and limb movements in patients with sleep bruxism.

BACKGROUND: Most rhythmic masticatory muscle activities (RMMAs) have been shown to be accompanied with limb movements (LMs) in sleep bruxism (SB) patients during sleep. OBJECTIVES: To compare the relationships between RMMAs and LMs in SB patients and normal subjects. METHODS: Polysomnographic recordings were performed on eight SB patients and nine normal subjects and the frequencies and durations of RMMAs as well as LMs were determined. Linear regression and correlation analysis were performed to study the relationship between durations of RMMAs and LMs when RMMAs occurred with LMs. RESULTS: Most LMs in SB patients, but not in normal subjects, were accompanied with RMMAs. RMMAs in SB patients were more likely to be isolated, phasic or mixed, while RMMAs in normal subjects were more likely to be tonic. The frequencies of LMs, isolated RMMAs and RMMAs accompanied with LMs in SB patients were significantly higher than those in normal subjects. Furthermore, linear regression and correlation analysis showed that duration of RMMAs was significantly associated with that of LMs when RMMAs occurred with LMs. The duration of RMMAs, when accompanied with LMs, in SB patients was significantly longer than that in normal subjects. CONCLUSIONS: Close relationships between LMs and RMMAs exist in SB patients and normal subjects, and SB episodes may be part of cortical arousal responses and the increased cortical activities associated with SB episodes may not just be localised to the central nervous system (CNS) that controls jaw movements but may also include other parts of CNS that controls LMs.

Trigger points are associated with widespread pressure pain sensitivity in people with tension-type headache.

Objective To investigate the association between trigger points (TrPs) and widespread pressure pain sensitivity in people with tension-type headache (TTH) and to determine if this association is different between frequent episodic (FETTH) or chronic (CTTH) headache. Design A cross-sectional study. Methods One hundred and fifty-seven individuals (29% male) with TTH participated. Clinical features of headache, i.e., intensity, duration, and frequency, were recorded in a headache diary. Active and latent TrPs were bilaterally explored in the temporalis, masseter, suboccipital, upper trapezius, sternocleidomastoid, and splenius capitis muscles. Pressure pain thresholds (PPT) were assessed over the trigeminal area (i.e., temporalis muscle), extra-trigeminal (i.e., C5/C6 zygapophyseal joint), and two distant pain-free points (i.e., second metacarpal and tibialis anterior muscle). Results Eighty (51%) patients were classified as FETTH, whereas 77 (49%) were classified as CTTH. No differences in the number of either active or latent TrPs (all p > 0.171) or widespread pressure pain sensitivity (all p > 0.351) were observed between FETTH and CTTH groups. The number of active and latent TrPs was significantly and negatively associated with PPTs: The higher the number of active or latent TrPs, the lower the widespread PPT, and the more generalized sensitization. This association was stronger within the FETTH group than the CTTH group. Conclusions This study found that the number of TrPs in head and neck/shoulder muscles was associated with widespread pressure hypersensitivity independently of the frequency of headache.

Acid-induced experimental knee pain and hyperalgesia in healthy humans.

Inflammation and the related acidity in peri-articular structures may be involved in pain generation and hyperalgesia in knee osteoarthritis. This study investigated pain and associated hyperalgesia provoked by infusion of acidic saline into the infrapatellar fat pad. Twenty-eight subjects participated in two sessions in which acidic saline (AS, pH 5) or neutral saline (NS, pH 7.4) were infused into the infrapatellar fat pad for 15 min. Pain intensity, pain area, mechanical and thermal sensitivity, and maximal voluntary knee extension force were recorded. Repeated infusions were performed in 14 subjects. Infusion of AS caused significantly higher pain intensity, larger pain areas, induced hyperalgesia around the infused knee, and reduced extension force. No significant pain facilitation or spreading of hyperalgesia was found after repeated infusions as compared with single infusions. Acidic saline infused into the infrapatellar fat pad provoked pain and localized mechanical hyperalgesia. Thus, this acid-induced pain model may mimic the early-stage responses to tissue injury of knee osteoarthritis.

Quantitative sensory testing for assessment of somatosensory function in human oral mucosa: a review.

OBJECTIVE: This narrative review provides an overview of the quantitative sensory testing (QST) to assess somatosensory function in human oral mucosa. MATERIAL AND METHODS: A literature search was conducted in the PubMed database to identify studies in vivo on human oral mucosa using QST methods. A list of 149 articles was obtained and screened. A total of 36 relevant articles remained and were read in full text. Manual search of the reference lists identified eight additional relevant studies. A total of 44 articles were included for final assessment. RESULTS: The included studies were divided into six categories according to the study content and objective. In each category, there was a great variety of aims, methods, participants and outcome measures. The application of QST has nevertheless helped to monitor somatosensory function in experimental models of intraoral pain, effects of local anesthesia, after oral and maxillofacial surgery and after prosthodontic and orthodontic treatment. CONCLUSIONS: QST has been proved to be sufficiently stable and reliable, and valuable information has been obtained regarding somatosensory function in healthy volunteers, special populations and orofacial pain patients. However, as most of the studies were highly heterogeneous, the results are difficult to compare quantitatively. A standardized intraoral QST protocol is recommended and expected to help advance a mechanism-based assessment of neuropathies and other intraoral pain conditions.

Quantitative sensory testing (QST) in the orofacial region of healthy Chinese: influence of site, gender and age.

OBJECTIVE: To establish a preliminary thermal and mechanical somatosensory profile using a standardized quantitative sensory testing (QST) to investigate site, gender and age differences in healthy Chinese. MATERIALS AND METHODS: Twenty younger (age: 20-40 years, 10 men, 10 women) and twenty older (age: 41-61 years, 10 men, 10 women) healthy participants completed the study. Cold detection threshold (CDT), warm detection threshold (WDT), cold pain threshold (CPT), heat pain threshold (HPT), mechanical detection threshold (MDT) and mechanical pain threshold (MPT) were measured at five sites: Left hand, bilaterally at the mental area, tip of tongue and the lower lip mucosa. Mixed model ANOVAs with repeated measures were used to analyze the data. RESULTS: MDT(p < .001) and MPT (p < .05) were significantly higher on the hand compared to the mental areas. The CDT ( p = .006) was significantly higher and WDT (p < .001) was significantly lower at the tongue compared to lip mucosa and CDT (p < .001) was higher at the tongue mucosa than at the mental areas. WDT (p < .001) and HPT (p < .05) were significantly higher at the tip of the tongue and the lower lip mucosa compared to the mental areas. Significantly lower sensitivity for WDT (p < .001) and CDT (p = .004) were found in the older group compared to the younger group. Significant gender differences were found with less sensitivity for WDT (p = .024) and MDT (p = .003) in men compared to women. CONCLUSIONS: Application of standardized QST can provide valuable information of orofacial somatosensory phenotypes in a Chinese population. Age, gender and site are mandatory to control for.

Identification of subgroups of patients with tension type headache with higher widespread pressure pain hyperalgesia.

BACKGROUND: Identification of subgroups of patients with different levels of sensitization and clinical features can help to identify groups at risk and the development of better therapeutic strategies. The aim of this study was to identify subgroups of patients with tension type headache (TTH) with different levels of sensitization, clinical pain features, and psychological outcomes. METHODS: A total of 197 individuals with TTH participated. Headache intensity, frequency, and duration and medication intake were collected with a 4-weeks diary. Pressure pain thresholds were assessed bilaterally over the temporalis muscle, C5-C6 joint, second metacarpal and tibialis anterior muscle to determine widespread pressure pain hyperalgesia. The Hospital Anxiety and Depression Scale assessed anxiety and depression. The State-Trait Anxiety Inventory evaluated the state and trait levels of anxiety. The Headache Disability Inventory evaluated the burden of headache. Health-related quality of life was determined with the SF-36 questionnaire. Groups were considered as positive (three or more criteria) or negative (less than three criteria) on a clinical prediction rule: headache duration <8.5 h/day; headache frequency <5.5 days/week; bodily pain <47 and vitality <47.5. RESULTS: The ANCOVA revealed that subjects in group 1 (positive rule, n = 89) exhibited longer headache history, shorter headache duration, lower headache frequency, higher widespread pressure hyperalgesia, higher anxiety trait levels, and lower quality of life (all, P < 0.01) than those subjects within group 2 (negative rule, n = 108). Differences were similar between men and women. CONCLUSIONS: This study identified a subgroup of patients with TTH with higher sensitization, higher chronicity of headaches and worse quality of life but lower frequency and duration of headache episodes. This subgroup of individuals with TTH may need particular attention and specific therapeutic programs for avoiding potential chronification.

The association of headache frequency with pain interference and the burden of disease is mediated by depression and sleep quality, but not anxiety, in chronic tension type headache.

BACKGROUND: A better understanding of potential relationship between mood disorders, sleep quality, pain, and headache frequency may assist clinicians in determining optimal therapeutic programs. The aim of the current study was to analyze the effects of sleep quality, anxiety, depression on potential relationships between headache intensity, burden of headache, and headache frequency in chronic tension type headache (CTTH). METHODS: One hundred and ninety-three individuals with CTTH participated. Headache features were collected with a 4-weeks headache diary. The Hospital Anxiety and Depression Scale was used for assessing anxiety and depression. Headache Disability Inventory evaluated the burden of headache. Pain interference was determined with the bodily pain domain (SF-36 questionnaire). Sleep quality was assessed with Pittsburgh Sleep Quality Index. Path analyses with maximum likelihood estimations were conducted to determine the direct and indirect effects of depression, anxiety, and sleep quality on the frequency of headaches. RESULT: Two paths were observed: the first with depression and the second with sleep quality as mediators. Direct effects were noted from sleep quality, emotional burden of disease and pain interference on depression, and from depression to headache frequency. The first path showed indirect effects of depression from emotional burden and from sleep quality to headache frequency (first model R 2 = 0.12). Direct effects from the second path were from depression and pain interference on sleep quality and from sleep quality on headache frequency. Sleep quality indirectly mediated the effects of depression, emotional burden and pain interference on headache frequency (second model R 2 = 0.18). CONCLUSIONS: Depression and sleep quality, but not anxiety, mediated the relationship between headache frequency and the emotional burden of disease and pain interference in CTTH.