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?p?p?=?.006) was significantly higher and WDT (p?p?p?p?p?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.     

Recommendations for evaluating agents for the reduction of dentinal hypersensitivity

*The following committee members were nominated by the Council on Dental Therapeutics and appointed by President Bentley: Dr. Major M. Ash, Jr., Professor and Chairman, Department of Occlusion, School of Dentistry, University of Michigan; Dr. Mohandas Bhat, Assistant Professor, Department of Community Dentistry, Case Western Reserve University; Dr. Nabil Bissada, Professor and Chairman, Department of Periodontics, School of Dentistry, Case Western Reserve University; Dr. Sebastian G. Ciancio, Professor and Chairman, Department of Periodontics, School of Dentistry, State University of New York at Buffalo; Dr. Louis P. Gangarosa, Professor and Coordinator of Pharmacology, School of Dentistry, Medical College of Georgia; Dr. Hans Graf, Chairman, Department of Periodontology, School of Dentistry, University of Bern (Switzerland); Dr. Isreal Klineberg, Chairman, Department of Oral Biology and Pathology, School of Dentistry, State University of New York at Stony Brook; Dr. Joseph A. Kanapka, Assistant Director, Dental Research, Vicks Research Center; Dr. Synguck Kim, Assistant Professor, Department of Endodontics, College of Dental and Oral Surgery, Colombia University; Dr. Walter T. McFall, Jr., Professor, Department of Periodontology, School of Dentistry, University of North Carolina; Dr. Patricia A. McGrath, Director, Pain Research Unit, Department of Oral Biology, Faculty of Dentistry, University of Western Ontario; Dr. David A. Pashley, Professor, Department of Oral Biology-Physiology, School of Dentistry, Medical College of Georgia; Dr. Gerald Silverman, Private Practice, Hartford, Connecticut. Chairing the committee meeting were the following American Dental Association Staff Members: Dr. Kenneth H. Burrell, Assistant Secretary, Council on Dental Therapeutics; Dr. Conrad A. Naleway, Director, Division of Chemistry, Council on Dental Therapeutics; Dr. Helmut Zander, Special Consultant for Scientific Affairs, American Dental Association. The committee was funded by the American Fund for Dental Health through the support of the Block Drug Company, the John O. Butler Company, the Mentholaltim Company, and Richardson-Vicks, Inc.     

Assessment of pain in cervical dentinal sensitivity studies

Abstract Traditionally cervical dentinal sensitivity (CDS) has been evaluated mainly subjectively on the basis of the individual patient's subjective response, e.g., in the form of verbal rating and visual analogue scales and questionnaires. The stimuli used for evaluating this response can be grouped into 4 main categories: mechanical, chemical, electrical and thermal. This review of the literature, however, indicates that there are problems in evaluating patient subjective response to these various test stimuli used in the assessment and treatment of CDS. Opinions also vary as to the reliability of some of these methods of assessment, although recently, efforts have been made to develop controlled reproducible stimuli more suited to the evaluation of CDS. Currently no single method of eliciting and assessing CDS may be considered ideal. Further research is required to evaluate suitable methodology for the quantification of realistic test stimuli under controlled clinical conditions, whereby the subjective response may be objectively measured by the investigator.     

Clinical evaluation of a potassium nitrate dentifrice for the treatment of dentinal hypersensitivity

Abstract The effectiveness of a 5% potassium nitrate dentifrice as a daily home treatment for dentinal hypersensitivity was evaluated in a double-blind study in 36 Japanese subjects who complained of cold and/or tactile hypersensitivity. The subjects were divided into 2 groups, with 18 being given a 5% potassium nitrate dentifrice (treated group) and the other 18 a vehicle paste (control group). Both groups were instructed to brush their teeth 2 × a day. The hypersensitivity levels of the affected teeth were assessed by 2 stimuli, one tactile and the other cold air, and by the perception of pain. The results of all 3 assessment methods indicated that the potassium nitrate dentifrice significantly decreased the level of hypersensitivity at weeks 4, 8, and 12. In the treated group, a rapid decrease of positive scores for both the cold air stimulus and the subjective symptoms appeared from week 2. Although a significant decrease of the assessment score was also observed in the control group, the reduction rate of the score was much greater in the treated group by ail 3 assessment methods at weeks 4, 8, and 12. Complete relief of subjective symptoms throughout the 12 weeks’examination was noted in 67% of the subjects in the treated group, but in only 6% in the control group. These results suggest the usefulness of a 5% potassium nitrate dentifrice in Japanese patients with dentinal hypersensitivity.     

Statistical analysis and design characteristics of studies on dentinal sensitivity

Abstract This paper discusses the role of statistics in the design and data analysis of studies on dentinal sensitivity. Topics covered include selection of study subjects, estimation of sample size, assigning subjects to experimental and control groups and choosing the appropriate statistical analysis.     

定量感觉测试在三叉神经区域应用的研究初探

目的:采用定量感觉测试(quantitative sensory testing,QST)探讨年轻人群的三叉神经区域感觉的差异。方法:选择40例健康志愿者,男、女各20例,平均(24.4±3.52)岁。在眶下神经分布区域(V2)、下颌神经分布区域(V3)的左右侧分别测量冷/热感觉阈值(CDT/WDT)、冷/热疼痛阈值(CPT/HPT)、机械感觉阈值(MDT)和机械疼痛阈值(MPT),采用两因素的方差分析进行数据统计。结果:女性的CDT值较男性低,表明对冷觉刺激更为迟钝(P=0.002);女性的WDT值较男性低,表明对温觉刺激更为敏感(P=0.012);女性的HPT值较男性低,表明对热痛刺激更为敏感(P=0.034)。V2比V3对热痛刺激更为敏感(P<0.001),对冷觉刺激更为迟钝(P=0.001),差异有统计学意义。V2、V3左右两侧的QST各项指数均无差异。结论:温度和机械的定量感觉测试可作为评价三叉神经区域感觉功能状况的一种手段。     

Agreement between quantitative and qualitative sensory testing of changes in oro‐facial somatosensory sensitivity

Qualitative somatosensory testing (QualST) is a simple chairside test. It can be used to roughly assess the presence or absence of altered somatosensory function. To use QualST clinically, it is important to assess its agreement with quantitative sensory testing (QST). The aims of this study were to assess the agreement between QST and QualST when testing the modulation of facial sensitivity by capsaicin in healthy participants and to explore the agreement between QST and QualST in assessing the intraoral sensory function in clinical atypical odontalgia (AO) patients. Eighteen healthy pain‐free adults and data from 27 AO patients were included in the study. Thirteen QST and three QualST parameters were evaluated at each site. Z‐scores were computed for healthy participants, and Loss‐Gain scores were created. The agreement observed between QST and QualST in participants with no alterations in facial sensation (placebo) was good, that is ranging from 89% to 94%. A poorer agreement was seen after capsaicin application in all test modalities with agreement ranging from 50% to 72%. The commonest misclassification observed was participants classified as normal according to QST, but hyper‐ or hyposensitive according to QualST after capsaicin application, especially for cold and pinprick. A similar trend was observed in AO patients where patients classified as normal using QST were misclassified as hypersensitive and in few patients as hyposensitive by QualST. In conclusion, the study showed that QualST may be used as a screening tool in the clinical setting, especially to show that subjects have normal sensory function.     

Use of multiple sensitivity measurements and log it statistical analysis to assess the effectiveness of a potassium-citrate-containing dentifrice in reducing dentinal hypersensitivity

A potassium citrate-SMFP containing dentifrice was tested in a double-blind 8-week clinical trial on subjects with a history of dentinal hypersensitivity. A dentifrice containing SMFP but no potassium salt was used as the control and a 2nd test dentifrice containing potassium nitrate-SMFP was assessed at the same time. The sensitivity of the subjects was evaluated at 0, 3 and 8 weeks using electrical and tactile methods plus a 1-s air blast. The sensitivity scores for each subject at each examination were summarised as a proportion of the examined teeth deemed sensitive. Assessment of any effects of the dentifrices was via an analysis of covariance of the logit transformation of these proportions with the baseline value as the covariate. The use of this novel method of analysis had the advantage of taking into account changes in sensitivity of all of the teeth, both sensitive and non-sensitive, since electrical measurements indicated effects on both. Of the original 120 subjects, 111 completed the trial and the 3 dentifrice groups remained well balanced for age, sex and sensitivity. All 3 dentifrice groups showed statistically significant reductions in sensitivity over the 8 weeks. However, the potassium citrate-SMFP dentifrice was significantly more effective than either the control SMFP dentifrice, or the potassium nitrate-SMFP dentifrice, at reducing sensitivity after 3 weeks, and this difference plus further sensitivity reduction with all 3 dentifrices was observed after 8 weeks.     

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.     

健康人群的颌面部定量感觉研究

目的 探讨中国人群三叉神经和躯干神经的定量感觉在部位、年龄及性别之间的差异。方法 选择青年组和中年组健康志愿者各20例,在手背、舌尖、下唇及左右颏部分别测量冷/热感觉阈值（CDT/WDT）、冷/热疼痛阈值(CPT/HPT)、机械感觉阈值(MDT)和机械疼痛阈值(MPT),采用重复设计的方差分析进行数据分析。结果 三叉神经分布区域的温度和机械敏感性比手背皮肤高,颏部皮肤的温度敏感性比口内黏膜高;青年组比中年组对温度感觉刺激和机械刺激更为敏感,差异有统计学意义;女性对温度疼痛刺激更为敏感,差异有统计学意义。结论 温度和机械定量感觉测试的应用可以更好的理解不同感觉表型背后的机制,并且为对中国人群三叉神经区域感觉异常方面的研究提供一些基本信息。     

Thermal transfer in extracted incisors during thermal pulp sensitivity testing

AIM: To measure the temperature distribution within tooth structure during and after application of thermal stimuli used during pulp sensitivity testing. METHODOLOGY: Extracted intact human maxillary anterior teeth were investigated for temperature changes at the labial enamel, the dentino-enamel junction (DEJ) and pulpal surface during and after a 5-s application of six different thermal stimuli: hot water (80 degrees C), heated gutta-percha (140 degrees C), carbon dioxide dry ice (-72 degrees C), refrigerant spray (-50 degrees C), ice stick (0 degrees C) and cold water (2 degrees C). J-type thermocouples and heat conduction paste were used to detect temperature changes, together with a data acquisition system (Labview). Data were analysed using analysis of variance, with a confidence level of P < 0.05. RESULTS: Temperature change was detected more quickly at the DEJ and pulpal surface with the application of hot water, heated gutta-percha and refrigerant spray than with carbon dioxide dry ice and ice (P < 0.05). Cold water and refrigerant spray were in the same range in terms of time to detect temperature change at both the DEJ and pulpal surface. Thermal stimuli with greater temperature difference from tooth temperature created a greater thermal gradient initially, followed by a greater temperature change at the DEJ and the pulpal surface. In this regard, ice and cold water were weaker stimuli than others (P < 0.05). CONCLUSIONS: Thermal stimuli used in pulp testing are highly variable in terms of temperature of the stimulus, rate of thermal transfer to the tooth and extent of temperature change within tooth structure. Overall, dry ice and refrigerant spray provide the most consistent stimuli, whereas heated gutta-percha and hot water were highly variable. Ice was a weak stimulus.     

Er:YAG激光联合3M ESPE Adper Easy-one粘结剂堵塞牙本质小管的体外研究

目的:研究Er:YAG激光联合3M ESPE Adper Easy-one自酸蚀树脂粘结剂堵塞牙本质小管的效果,为其治疗牙本质敏感提供实验室依据。方法:选择因正畸需要拔除的牙体完整、无龋损的前磨牙8个,制备牙颈部牙本质小管暴露的牙本质样本32个,按处理方法不同随机分为4组:空白对照组、Er:YAG激光处理组、3M ESPE Adper Easy-one粘结剂处理组、Er:YAG激光、3M ESPE Adper Easy-one粘结剂联合处理组,扫描电镜下比较牙本质表面超微形态、纵断面的粘结剂牙本质界面的混合层、树脂突的微观表现,观察牙本质小管的堵塞效果。结果:Er:YAG激光联合3M ESPE Adper Easy-one粘结剂组与粘结剂组的堵塞牙本质小管的表面微观形态类似,牙本质小管被完全堵塞;激光处理组的牙本质小管基本完全堵塞;纵断面观察联合组粘结界面可见到清晰的混合层和树脂突,且树脂突深度较粘结剂组明显增加,激光组纵断面牙本质小管内无明显堵塞物。结论:Er:YAG激光与3M ESPE Adper Easy-one粘结剂联合处理能够有效的堵塞牙本质小管。     

Reliability of intra‐oral quantitative sensory testing (QST) in patients with atypical odontalgia and healthy controls – a multicentre study

The reliability of comprehensive intra‐oral quantitative sensory testing (QST) protocol has not been examined systematically in patients with chronic oro‐facial pain. The aim of the present multicentre study was to examine test–retest and interexaminer reliability of intra‐oral QST measures in terms of absolute values and z‐scores as well as within‐session coefficients of variation (CV) values in patients with atypical odontalgia (AO) and healthy pain‐free controls. Forty‐five patients with AO and 68 healthy controls were subjected to bilateral intra‐oral gingival QST and unilateral extratrigeminal QST (thenar) on three occasions (twice on 1 day by two different examiners and once approximately 1 week later by one of the examiners). Intra‐class correlation coefficients and kappa values for interexaminer and test–retest reliability were computed. Most of the standardised intra‐oral QST measures showed fair to excellent interexaminer (9–12 of 13 measures) and test–retest (7–11 of 13 measures) reliability. Furthermore, no robust differences in reliability measures or within‐session variability (CV) were detected between patients with AO and the healthy reference group. These reliability results in chronic orofacial pain patients support earlier suggestions based on data from healthy subjects that intra‐oral QST is sufficiently reliable for use as a part of a comprehensive evaluation of patients with somatosensory disturbances or neuropathic pain in the trigeminal region.     

Test–retest reliability of quantitative sensory testing for mechanical somatosensory and pain modulation assessment of masticatory structures

Assessing the reliability of medical measurements is a crucial step towards the elaboration of an applicable clinical instrument. There are few studies that evaluate the reliability of somatosensory assessment and pain modulation of masticatory structures. This study estimated the test–retest reliability, that is over time, of the mechanical somatosensory assessment of anterior temporalis, masseter and temporomandibular joint (TMJ) and the conditioned pain modulation (CPM) using the anterior temporalis as the test site. Twenty healthy women were evaluated in two sessions (1 week apart) by the same examiner. Mechanical detection threshold (MDT), mechanical pain threshold (MPT), wind‐up ratio (WUR) and pressure pain threshold (PPT) were assessed on the skin overlying the anterior temporalis, masseter and TMJ of the dominant side. CPM was tested by comparing PPT before and during the hand immersion in a hot water bath. anova and intra‐class correlation coefficients (ICCs) were applied to the data (α = 5%). The overall ICCs showed acceptable values for the test–retest reliability of mechanical somatosensory assessment of masticatory structures. The ICC values of 75% of all quantitative sensory measurements were considered fair to excellent (fair = 8·4%, good = 33·3% and excellent = 33·3%). However, the CPM paradigm presented poor reliability (ICC = 0·25). The mechanical somatosensory assessment of the masticatory structures, but not the proposed CPM protocol, can be considered sufficiently reliable over time to evaluate the trigeminal sensory function.     

Somatosensory profiling of intra‐oral capsaicin and menthol in healthy subjects

This study was designed to investigate the effect of surrogate orofacial pain models on the quantitative sensory testing (QST) profile in healthy participants. Capsaicin, menthol, or saline (control) were applied topically onto the gingiva of 15 healthy subjects for 15 min. During application, the subjects rated pain intensity on a score of 0–10, on an electronic visual analog scale (VAS). A standardized intra‐oral QST protocol was performed before and immediately after application. Data obtained before and after application were compared using rank‐sum tests, and QST profiles were made after Z‐transformation. Application of capsaicin caused moderate levels of pain (VAS_peak = 6.0 ± 0.7), and application of menthol produced mild levels of pain (VAS_peak = 1.8 ± 0.6). Capsaicin induced hypersensitivity to warmth, heat pain and cold pain and hyposensitivity to mechanical stimuli. Menthol induced hypersensitivity to cold and warmth. Saline caused hypersensitivity to heat pain and hyposensitivity to mechanical stimuli. However, somatosensory profiles from Z‐scores demonstrated sensory gains regarding warmth detection and heat pain only after application of capsaicin. In conclusion, a standardized battery of QST showed somatosensory changes after application of capsaicin, menthol and saline to the gingiva. However, the Z‐score‐based profiles may only reflect the most prominent somatosensory changes and thus represent a conservative approach for evaluation of data.