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AIMS: To systematically compare clinical findings and psychosocial factors between patients suffering from atypical odontalgia (AO) and an age- and gender-matched group of patients with temporomandibular disorders (TMD). METHODS: Forty-six AO patients (7 men and 39 women; mean age, 56 years) were compared with 41 TMD patients (8 men and 33 women; mean age, 58 years). RESULTS: Mean pain intensity at the time of inclusion in the study was similar between the groups (TMD: 5.3 +/- 0.4, AO: 5.0 +/- 0.3), but pain duration was longer in AO patients (AO: 7.7 +/- 1.1 years, TMD: 4.5 +/- 0.1 years). Eighty-three percent of the AO patients and 15% of TMD patients reported pain onset in relation to dental/surgical procedures. Episodic tension-type headache (TTH) occurred equally in both groups (TMD: 46%, AO: 46%), but TMD patients more frequently experienced chronic TTH (TMD: 35%, AO: 18%), myofascial TMD (TMD: 93%, AO: 50%), and temporomandibular joint disorders (TMD: 66%, AO: 2%). Overall, TMD patients had lower pressure pain thresholds and poorer jaw function than AO patients. Mean depression and somatization scores were moderate to severe in both groups, and widespread pain was most common in TMD patients. CONCLUSION: AO and TMD share some characteristics but differ significantly in report of dental trauma, jaw function, pain duration, and pain site. [ABSTRACT FROM AUTHOR]

AIMS: To use 2 well-characterized stimuli, the intraoral capsaicin model and the 'nociceptive-specific' electrode, to compare superficial nociceptive function between patients with atypical odontalgia (AO) and matched healthy controls. Furthermore, the authors aimed to describe the sensitivity, specificity, and positive predictive values (PPV) of the techniques if group differences could be established. METHODS: Thirty-eight patients with AO and 27 matched healthy controls participated in this study. Thirty microliters of 5% capsaicin was applied to the gingiva on the left and right sides of all participants as a pain-provocation test. The participants scored the capsaicin-evoked pain continuously on a 0-to-10 visual analog scale (VAS). Furthermore, individual electrical sensory and pain thresholds to stimulation with a 'nociceptive-specific' electrode on the facial skin above the infraorbital or mental nerve were determined. RESULTS: AO patients had higher VAS pain scores for capsaicin application than healthy controls (ANOVA: F > 4.88; P < .029). No differences between the painful sides and the nonpainful sides of the patients were found (ANOVA: F < 1.26; P > .262). No main effects of group or stimulation side on the electrical sensory and pain thresholds were detected (ANOVA: F < 0.309; P > .579). Sensitivity was 0.51; specificity, 0.81; and PPV, 0.77 when a VAS value of > or = 8 for capsaicin-evoked pain was used. CONCLUSION: AO patients show increased sensitivity to intraoral capsaicin but normal sensitivity to 'nociceptive-specific' electrical stimulation of the face in an area proximal to the painful site. The use of the intraoral pain-provocation test with capsaicin as a possible adjunct to the diagnostic workup is hampered by the only moderately good sensitivity and specificity. [ABSTRACT FROM AUTHOR]

AIMS: To use the human blink reflex (BR) to explore possible neuropathic pain mechanisms in patients with atypical odontalgia (AO). METHODS: In 13 AO patients, the BR was elicited using a concentric electrode and recorded bilaterally with surface electromyographic (EMG) electrodes on both orbicularis oculi muscles. Electrical stimuli were applied to the skin above branches of the V1, V2, and V3 nerves and to the V branch contralateral to the painful branch. Sensory and pain thresholds were determined. The BR examination of the painful V branch was repeated during a capsaicin pain-provocation test. The data were analyzed with nonparametric statistics. RESULTS: The BR responses (R2 and R3) evoked by stimulation of V3 were significantly smaller than the BR responses evoked by stimulation of V1 and V2 (P < .004). There were no differences in BR (R2 or R3) between the painful and nonpainful sides (P > .569), and the BR (R2 and R3) was not significantly modulated by experimental pain (P > .080). The sensory thresholds were significantly lower on the painful side compared to the nonpainful side (P = .014). The pain thresholds were not different between sides (P > .910). CONCLUSION: No major differences between the V nociceptive pathways on the right and left sides were found in a relatively small group of AO patients. Future studies that compare BRs in AO patients and healthy volunteers are needed to provide further knowledge on the pain mechanisms in AO. [ABSTRACT FROM AUTHOR]

This article provides a brief overview of the tools and methods that may be useful to assess neuropathic trigeminal pain. Pain is a complex multidimensional and biopsychosocial experience. While the assessment of neuropathic trigeminal pain is complex, there are several meaningful ways available for the systematic assessment of neuropathic pain and its effects and manifestations. The key to such an analysis is a standardized pain history and examination and a good knowledge of pain mechanisms. Patients can be asked to provide detailed information about their spontaneous pain (ie, stimulus-independent pain), eg, quality, intensity, localization, time course, and modifying factors. Stimulus-dependent pain components can be characterized with clinical examination procedures and quantitative psychophysical techniques such as application of mechanical, thermal, chemical, and electrical stimuli. The description of the stimulus-dependent pain is important to reveal the function of the somatosensory system and to map the extent of hyperalgesia, hyperesthesia and allodynia, because the normal relationship between stimulus intensity and perceived intensity is distorted in many neuropathic pain conditions. In addition to the psychophysical techniques, a number of laboratory tests for assessment of trigeminal pain have been developed and tested, although critical information on sensitivity, specificity, and predictive values is still scarce. There is also a need for common guidelines on classification, diagnostic procedures, and management. This will require concerted international, interdisciplinary action. [ABSTRACT FROM AUTHOR]

AIM: To examine, in a double-blind and placebo-controlled crossover manner, the effect of topical application of capsaicin on the alveolar mucosa with a battery of intraoral quantitative sensory testings (QST) in 16 healthy volunteers. METHODS: Thirty microL of 5 mg/mL capsaicin or vehicle (control) was applied to a 3 x 3-mm paper disk and applied to the alveolar mucosa under an oral bandage. The subjects rated the perceived pain intensity on a 0 to 10 electronic visual analog scale (VAS) for 15 minutes. Quantitative sensory testings were performed before and immediately after the 15-minute application and consisted of assessments of cold detection threshold, warmth detection threshold (WDT), cold pain threshold, beat pain threshold (HPT), mechanical sensitivity to single and repeated punctate mechanical stimulation with von Frey filaments and to single and repeated brush stimulation with a cotton swab, and detection and pain thresholds to electrical stimulation of the alveolar mucosa and maxillary first premolar tooth. Analysis of variance was used to test the data. RESULTS: Application of capsaicin caused moderate levels of pain (VASpeak scores 5.0 +/- 1.9) whereas the vehicle was practically painless (VASpeak 0.9 +/- 2.4). No significant effects of vehicle on QST could be detected (P > .143). In contrast, capsaicin application was associated with significant decreases in WDT and HPT (P < .001). No other significant changes in QST were observed for capsaicin application. CONCLUSION: The intraoral capsaicin pain model is associated with signs of heat hyperalgesia, but not mechanical hyperalgesia. Since the somatosensory sensitivity is not well characterized in most orofacial pain conditions, mainly due to lack of tradition and techniques, intraoral QST may provide a better description of the somatosensory sensitivity and underlying mechanisms in orofacial pain conditions. [ABSTRACT FROM AUTHOR]