Effect of clinical experience and training with visual feedback on standardized palpation outcomes-Potential implications for assessment of jaw muscle sensitivity.

BACKGROUND: The evaluation of muscle pain and sensitivity by manual palpation is an important part of the clinical examination in patients with myalgia. However, the effects of clinical experience and visual feedback on palpation of the masticatory muscles with or without a palpometer are not known. OBJECTIVE: To estimate the effects of clinical experience and visual feedback on the accuracy of palpation in standardized settings. METHODS: Thirty-two dentists (age 35 ± 11 years) classified as either specialists (n = 16) or generalists (n = 16) participated in this experiment. All dentists were instructed to target force levels of 500- or 1000-gf, as determined on an electronic scale using either standardized palpometers or manual palpation (MP). All dentists participated in four different tests: MP, MP with visual feedback (MPVF), palpometer (PAL) and PAL with visual feedback (PALVF). Actual force values for each type of palpation from 0 to 2, 2 to 5 and 0 to 5 s were analysed by calculating target force level. RESULTS: The relative differences during 2-5 and 0-5 s with 1000 gf were significantly lower for generalists than for specialists (p < .05). In generalists and specialists, the coefficients of variation and the relative differences during 2-5 s were significantly lower for PAL and PALVF than for MP (p < .05). CONCLUSIONS: These findings suggest that the use of a palpometer, but not clinical experience with palpation of masticatory muscles, increases the accuracy of palpation, and ≥2 s of palpation with a palpometer is optimal for masticatory muscles.

Standardized palpation of the temporalis muscle evoke referred pain and sensations in individuals without TMD.

OBJECTIVES: This study aimed to determine if standardized palpations of the temporalis muscle evoke referred pain and/or sensations in individuals without TMD. MATERIALS AND METHODS: This was a randomized, single-blinded study. The mechanical sensitivity of the right temporalis muscle was assessed in 32 participants without TMD with nine different stimulations to 15 test sites using palpometers (different stimulus intensities (0.5, 1.0, and 2.0 kg) and durations (2, 5, and 10 s). After each stimulus, participants were asked to score perceived pain intensity and intensity of unpleasantness on a 0-100 numeric rating scale as an indicator of mechanical sensitivity in the temporalis muscle and to indicate any areas of referred pain/sensations on a body chart. RESULTS: Pain intensity significantly differed between palpation durations, intensities, and test sites (P < 0.001). In contrast, unpleasantness significantly differed between palparation duration and intensities (P < 0.001), but not test sites. Participants more frequently reported referred pain/sensations evoked by the 10-s (34.4%) as opposed to the 2-s (6.3%) and 5-s (15.6%) palpation duration at the 2.0-kg stimulus intensity (P < 0.05). CONCLUSIONS: Our present results indicate that referred pain/sensations in the orofacial region can be evoked by standardized palpation of the temporalis muscle and influenced by the palpation duration in individuals without TMD. CLINICAL RELEVANCE: Referred pain/sensations from the temporalis muscle were duration- and intensity-dependent processes originating from local stimuli.

Drop homotopic effects of masseter-muscle pain on somatosensory sensitivity in healthy participants.

Current pain classifications use 1.0-kg palpation of the masseter muscle to distinguish between "pain patients" and "healthy controls" but a thorough understanding of the normal physiological responses to various somatosensory stimuli is lacking. The aim of this study was to investigate somatosensory function of the skin over the masseter muscle in healthy participants that were divided into a masseter pain prone group (MPP) (n = 22) and non-MPP group (n = 22), according to the response to a 1.0-kg palpation. Quantitative sensory testing (QST) was performed at the skin above the right masseter muscle (homotopic). In an additional experiment, 13 individuals each from MPP and non-MPP received application of 60% topical lidocaine tape to the skin over the masseter muscle for 30 min. Immediately after, mechanical pain sensitivity (MPS), dynamic mechanical allodynia, and pressure pain threshold were tested. Homotopic MPS was significantly higher and PPTs significantly lower in MPP than in N-MPP (P < 0.05). Strikingly, no other differences in QST outcomes were observed between the groups (P > 0.05). After lidocaine application, no significant differences in homotopic MPS were observed between groups. The presence or absence of acute provoked pain in masseter muscle is exclusively associated with differences in homotopic MPS which is decreased following topical anesthesia.

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.

Referred Pain and Sensations Evoked by Standardized Palpation of the Masseter Muscle in Healthy Participants.

AIMS: To determine if standardized palpation of the masseter muscle can evoke referred pain and/or sensations in healthy individuals and to compare the mechanical sensitivities in response to three different levels of palpation force. METHODS: A total of 32 pain-free individuals participated. The right masseter muscle was divided into 15 test sites. Mechanical sensitivity of the masseter was assessed with three mechanical stimuli (0.5 kg, 1.0 kg, or 2.0 kg) applied by palpometers to the 15 test sites for 5 seconds each site. Participants scored the perceived intensity of pain and unpleasantness of each of the three mechanical stimuli on 0-100 numeric rating scales (NRS). After each stimulus, the duration of aftersensation was measured, and the participants were also asked to indicate areas within the orofacial region with referred pain/sensations. Data were tested using analysis of variance, Tukey post hoc, and McNemar's tests with a 5% level of significance. RESULTS: Referred pain/sensations were most commonly evoked with the 2.0-kg stimulus (34.4% of participants; P < .05) compared to the 1.0-kg (12.5%) and 0.5-kg stimuli (3.1%). There were significant effects of stimulus intensity on NRS scores for pain and unpleasantness, as well as for aftersensation (P < .05). There were significant effects on NRS scores for pain and unpleasantness for the 1.0- and 2.0-kg stimuli (P < .05) and on aftersensation for the 2.0-kg stimulus (P < .05). CONCLUSION: These results indicate that referred pain/sensations in the orofacial region are frequent phenomena among healthy individuals during standardized palpation of the masseter muscle.

Effect of a repeated tongue-lift motor task for tongue function.

This study investigated the effect of repeated tongue motor tasks on suprahyoid muscle activity and tongue pressure. Fourteen participants performed three series of a standardized tongue-lift training (TLT) task on each of five consecutive days. Electromyographic (EMG) activity from suprahyoid muscles and tongue pressure were recorded. In the first and third TLT series, participants were instructed only to target different force levels. During the second TLT series, visual feedback of the force level was given. One series consisted of three measurements [at 10%, 20%, and 40% of maximum voluntary contraction (MVC), respectively]. The coefficient of determination of the target force level-EMG curve and the target force level-tongue pressure curve was calculated from all series. There were no statistically significant day-to-day differences in EMG-root mean square (RMS) values and tongue pressure during MVC. The coefficients of determination of tongue pressure in the first series on day 1 were statistically significantly lower than the coefficients of determination in the first series on day 5. These findings suggest that the control of tongue pressure improved, while the maximum force remained constant. These results could have implications for treatment paradigms related to learning for patients with compromised tongue function, such as swallowing disorders or dysphagia.

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.