Maria Pigg

Reliability of intraoral quantitative sensory testing (QST)

&NA; The German Research Network on Neuropathic Pain (DFNS) has recommended a protocol with 13 quantitative sensory testing (QST) measures for detecting somatosensory abnormalities. Reliability is an important scientific property and has been adequately tested for cutaneous QST. This study evaluates intraoral sites for which no reliability trials have yet been published. Inter‐ and intra‐examiner reliability of 13 QST measures at intra‐ and extraoral trigeminal sites were investigated. Twenty‐one healthy volunteers from Malmö University, Malmö, Sweden (13 women and 8 men, mean age 40.4 years, range 24–71) participated. Two independent examiners previously trained in the DFNS QST protocol examined the participants using the entire protocol. Each participant was examined twice on the same day, once by each examiner (inter‐examiner reliability). After 1–3 weeks, one examiner re‐examined all participants (intra‐examiner reliability). The measurements were made on the skin of the right cheek, the tip of the tongue, and bilaterally on the gingival mucosa of the upper premolar region. The intraclass correlation coefficient (ICC) or kappa was used to calculate variations. Most tests had acceptable to excellent inter‐examiner (ICC 0.41–0.89) and intra‐examiner (ICC 0.43–0.87) reliability. For each test, inter‐ and intra‐examiner reliabilities at intra‐ and extraoral sites were similar. No significant differences between right and left sides were found intraorally. We conclude that inter‐ and intra‐examiner reliabilities of most QST measures are acceptable for assessing somatosensory function in the orofacial region.

Guidelines and recommendations for assessment of somatosensory function in oro-facial pain conditions - a taskforce report

The goals of an international taskforce on somatosensory testing established by the Special Interest Group of Oro-facial Pain (SIG-OFP) under the International Association for the Study of Pain (IASP) were to (i) review the literature concerning assessment of somatosensory function in the oro-facial region in terms of techniques and test performance, (ii) provide guidelines for comprehensive and screening examination procedures, and (iii) give recommendations for future development of somatosensory testing specifically in the oro-facial region. Numerous qualitative and quantitative psychophysical techniques have been proposed and used in the description of oro-facial somatosensory function. The selection of technique includes time considerations because the most reliable and accurate methods require multiple repetitions of stimuli. Multiple-stimulus modalities (mechanical, thermal, electrical, chemical) have been applied to study oro-facial somatosensory function. A battery of different test stimuli is needed to obtain comprehensive information about the functional integrity of the various types of afferent nerve fibres. Based on the available literature, the German Neuropathic Pain Network test battery appears suitable for the study of somatosensory function within the oro-facial area as it is based on a wide variety of both qualitative and quantitative assessments of all cutaneous somatosensory modalities. Furthermore, these protocols have been thoroughly described and tested on multiple sites including the facial skin and intra-oral mucosa. Standardisation of both comprehensive and screening examination techniques is likely to improve the diagnostic accuracy and facilitate the understanding of neural mechanisms and somatosensory changes in different oro-facial pain conditions and may help to guide management.

Intraoral somatosensory abnormalities in patients with atypical odontalgia - A controlled multicenter quantitative sensory testing study

&NA; Intraoral somatosensory abnormalities were commonly detected in atypical odontalgia patients, and agreement between quantitative and qualitative sensory testing was good to excellent. &NA; Intraoral somatosensory sensitivity in patients with atypical odontalgia (AO) has not been investigated systematically according to the most recent guidelines. The aims of this study were to examine intraoral somatosensory disturbances in AO patients using healthy subjects as reference, and to evaluate the percent agreement between intraoral quantitative sensory testing (QST) and qualitative sensory testing (QualST). Forty‐seven AO patients and 69 healthy control subjects were included at Universities of Washington, Malmö, and Aarhus. In AO patients, intraoral somatosensory testing was performed on the painful site, the corresponding contralateral site, and at thenar. In healthy subjects, intraoral somatosensory testing was performed bilaterally on the upper premolar gingiva and at thenar. Thirteen QST and 3 QualST parameters were evaluated at each site, z‐scores were computed for AO patients based on the healthy reference material, and LossGain scores were created. Compared with control subjects, 87.3% of AO patients had QST abnormalities. The most frequent somatosensory abnormalities in AO patients were somatosensory gain with regard to painful mechanical and cold stimuli and somatosensory loss with regard to cold detection and mechanical detection. The most frequent LossGain code was L0G2 (no somatosensory loss with gain of mechanical somatosensory function) (31.9% of AO patients). Percent agreement between corresponding QST and QualST measures of thermal and mechanical sensitivity ranged between 55.6% and 70.4% in AO patients and between 71.1% and 92.1% in control subjects. In conclusion, intraoral somatosensory abnormalities were commonly detected in AO patients, and agreement between quantitative and qualitative sensory testing was good to excellent.

Chairside intraoral qualitative somatosensory testing: reliability and comparison between patients with atypical odontalgia and healthy controls.

AIMS To assess intraoral inter- and intraexaminer reliability of three qualitative measures of intraoral somatosensory function and to compare these measures between patients with atypical odontalgia (AO) and healthy controls. METHODS Thirty-one AO patients and 47 healthy controls participated. Inter- and intraexaminer reliability was tested on a subgroup of 46 subjects (25 AO; 21 healthy). Sensitivity to touch, cold, and pinprick stimuli was evaluated on the painful gingival site and the corresponding contralateral site in AO patients, and bilaterally on the gingiva of the first maxillary premolars in controls. Patients were asked to report hypersensitivity, hyposensitivity, or normal sensitivity to stimuli on the painful site compared with the nonpainful site. Kappa values were calculated, and chi-square and Fishers exact tests were used to compare frequencies between groups. RESULTS Kappa values ranged between 0.63 and 0.75. The frequency of hypersensitivity to either modality was significantly higher in patients (29% to 61%) than in controls (9% to 17%) (P < .015), whereas reports of hyposensitivity were similar between groups (2% to 16%) (P > .057). Only 3.2% of the AO patients had no reports of abnormal sensitivity on any of the tests, compared with 59.6% of the healthy subjects (P < .001). CONCLUSION Intraoral qualitative somatosensory testing can detect intraoral sensory disturbances in AO patients, and the reliability is sufficient for initial screening of orofacial somatosensory function.

Diagnostic yield of conventional radiographic and cone-beem computed tomographic images in patients with atypical odontalgia

AIM To investigate whether the additional diagnostic yield of a cone-beam computed tomography (CBCT) examination over conventional radiographs in patients primarily suspected of having atypical odontalgia (AO) improves differentiation between AO and symptomatic apical periodontitis (SAP) in patients with severe chronic intraoral pain. METHODOLOGY In this clinical study, 25 patients (mean age 54 ± 11 years, range 34-72) participated; 20 were diagnosed with AO and 5 with SAP. All patients were recruited from the clinics of the Faculty of Odontology, Malmö University. AO inclusion criteria were chronic pain (>6 months) in a region where a tooth had been endodontically or surgically treated, with no pathological cause detectable in clinical or radiologic examinations. SAP inclusion criteria were recurrent pain from a tooth diagnosed with apical periodontitis in clinical and radiographic examinations. Assessments comprised a self-report questionnaire on pain characteristics, a comprehensive clinical examination and a radiographic examination including panoramic and intraoral radiographs and CBCT images. The main outcome measure was periapical bone destruction. RESULTS Sixty per cent of patients with AO had no periapical bone destructions detectable with any radiographic method. Overall, CBCT rendered 17% more periapical bone destructions than conventional radiography. Average pain intensity in patients with AO was 5.6 (± 1.8) on a 0-10 numerical rating scale, and average pain duration was 4.3 (± 5.2) years. CONCLUSION Cone-beam computed tomography improves identification of patients without periapical bone destruction, which may facilitate differentiation between AO and SAP.

Seven-year follow-up of patients diagnosed with atypical odontalgia: a prospective study.

AIMS To examine the long-term prognosis of 46 previously examined atypical odontalgia (AO) patients. METHODS In 2002 and 2009, AO patients completed validated instruments measuring pain characteristics (pain frequency and intensity), physical functioning (Graded Chronic Pain Severity, GCPS) and emotional functioning (Symptoms Checklist, SCL-90R). The main outcome was global improvement. Baseline data on quantitative somatosensory testing and responsiveness to lidocaine injection were available for a subgroup of patients. Paired tests compared baseline and follow-up data, and logistic regression explored the possible prognostic value of baseline data. RESULTS Data from 37 patients (80%) were obtained. Thirteen patients (35%; 95% confidence intervals [CI] 20.2%-52.5%) rated their overall pain status as significantly improved, 22 (60%; 95% CI 42.1%-75.3%) as a little improved or unchanged, and two patients (5%; 95% CI 0.7%-18.2%) as worse. Five patients (14%; 95% CI 4.5%-28.8%) were pain-free, indicated by a characteristic pain intensity score of 0. Average pain intensity decreased (from 5.7 ± 2.0 to 3.5 ± 2.4; P < .001). Pain frequency (P < .001) and GCPS (P < .001) also decreased, whereas SCL-90R scores remained unchanged and 26 of the 37 patients reported ongoing treatment. Low baseline pain intensity was the only factor predictive of favorable outcome. CONCLUSION A third of the AO patients improved considerably over time, but for many of the patients, AO was a persistent and treatment-resistant condition.

A new protocol to evaluate the effect of topical anesthesia

This double-blind, placebo-controlled, randomized cross-over clinical experimental study tested the reliability, validity, and sensitivity to change of punctuate pain thresholds and self-reported pain on needle penetration. Female subjects without orofacial pain were tested in 2 sessions at 1- to 2-week intervals. The test site was the mucobuccal fold adjacent to the first upper right premolar. Active lidocaine hydrochloride 2% (Dynexan) or placebo gel was applied for 5 minutes, and sensory testing was performed before and after application. The standardized quantitative sensory test protocol included mechanical pain threshold (MPT), pressure pain threshold (PPT), mechanical pain sensitivity (MPS), and needle penetration sensitivity (NPS) assessments. Twenty-nine subjects, mean (SD) age 29.0 (10.2) years, completed the study. Test-retest reliability intraclass correlation coefficient at 10-minute intervals between examinations was MPT 0.69, PPT 0.79, MPS 0.72, and NPS 0.86. A high correlation was found between NPS and MPS (r = 0.84; P < .001), whereas NPS and PPT were not significantly correlated. The study found good to excellent test-retest reliability for all measures. None of the sensory measures detected changes in sensitivity following lidocaine 2% or placebo gel. Electronic von Frey assessments of MPT/MPS on oral mucosa have good validity.

Assessment of Mechanical Pain Thresholds in the Orofacial Region : A Comparison Between Pinprick Stimulators and Electronic Von Frey Device

AIMS To compare mechanical pain thresholds (MPTs) in the orofacial region assessed with two different approaches: with an electronic von Frey (EvF) device and with custom-made weighted pinprick stimulators. The test-retest reliability, variability of MPTs, and time duration of each test were also compared, as well as the ability of each test to create stimulus-response (S-R) curves. METHODS A total of 16 healthy volunteers participated. The MPT and S-R curve measurements were done with the two different techniques at three sites: on the skin of the right cheek (face), on the buccal gingival mucosa of the right upper premolar region (gingiva), and on the tip of the tongue (tongue). The same protocol was repeated 1 to 2 weeks later to determine test-retest reliability. RESULTS The MPT measurements with the EvF device were significantly faster (74.4 ± 20.8 seconds) than those with the pinprick stimulators (196.1 ± 33.0 seconds; P < .001). The absolute MPT values obtained with the EvF device were significantly higher than the values obtained with the pinprick stimulators at all test sites (P < .001). MPTs assessed with the EvF device showed higher reliability (intraclass correlation coefficient [ICC] = 0.77-0.94) than MPTs assessed with the pinprick stimulators (ICC = 0.57-0.84; P = .041). The reliability of the S-R curves was excellent for both methods with no significant differences between the methods (P = .403). CONCLUSION This study indicates that MPTs tested in the orofacial region with the EvF device were significantly higher than MPTs tested with the pinprick stimulators. However, the EvF device can be used with higher reliability and less time consumption for assessment of MPTs in the orofacial region than the pinprick stimulator technique, and also allows comparable construction of S-R curves.

Validity of Preoperative Clinical Findings to Identify Dental Pulp Status: A National Dental Practice-Based Research Network Study

INTRODUCTION Endodontic diagnostic tests are often used clinically to assess pulp status as a basis for the diagnosis and determination of whether root canal treatment (RCT) is indicated. Response to cold and pain on percussion are 2 common tests, yet their validity in identifying nonvital pulp in regular dental practice has not been reported. METHODS We assessed the validity of cold and percussion tests to identify nonvital pulp in teeth requiring RCT in a dental practice setting performed by 46 general dentists and 16 endodontists in the National Dental Practice-Based Research Network. The influence of patient-, tooth-, and dentist-related characteristics was investigated. Observed bleeding from the pulp chamber was the clinical reference. Sensitivity (SN), specificity (SP), overall test accuracy (TA), positive (PPV) and negative (NPV) predictive values, and likelihood and diagnostic odds ratios (LR+, LR-, dORs) were calculated for each single test and the combined cold and percussion tests. RESULTS Seven hundred eight patient teeth were included. Cold test showed high validity to identify a nonvital pulp status (SN = 89%, SP = 80%, TA = 84%, PPV = 81%, NPV = 88%, LR+ = 4.35, LR- = 0.14, dOR = 31.4), whereas pain on percussion had lower validity (SN = 72%, SP = 41%, TA = 56%, PPV = 54%, NPV = 60%, LR+ = 1.22, LR- = 0.69, dOR = 1.78). Combining the 2 tests did not increase validity, whereas preoperative pain, medication intake, patient age and sex, and dentist training level affected test validity significantly. CONCLUSIONS In regular dental practice, the cold test exhibits higher validity to discriminate between vital and nonvital pulp than the tooth percussion test.

A comparative analysis of magnetic resonance imaging and radiographic examinations of patients with atypical odontalgia.

AIMS To examine (1) the occurrence of magnetic resonance imaging (MRI) signal changes in the painful regions of patients with atypical odontalgia (AO) and (2) the correlation of such findings to periapical bone defects detected with a comprehensive radiographic examination including cone beam computed tomography (CBCT). METHODS A total of 20 patients (mean age 52 years, range 34 to 65) diagnosed with AO participated. Mean pain intensity (± standard deviation) was 5.6 ± 1.8 on a 0-10 numerical rating scale, and mean pain duration was 4.3 ± 5.2 years. The inclusion criterion was chronic pain (> 6 months) located in a region with no clear pathologic cause identified clinically or in periapical radiographs. In addition to a clinical examination and a self-report questionnaire, the assessments included radiographic examinations (panoramic, periapical, and CBCT images), and an MRI examination. Changes in MRI signal in the painful region were recorded. Spearmans rank correlation between radiographic and MRI findings was calculated. RESULTS Eight of the patients (40%) had MRI signal changes in the pain region. The correlation to radiographic periapical radiolucencies was 0.526 (P = .003). Of the eight teeth displaying changes in MRI signal, six showed periapical radiolucency in the radiographs. CONCLUSION MRI examination revealed no changes in the painful region in a majority of patients with AO, suggesting that inflammation was not present. MRI findings were significantly correlated to radiographic findings.