Grey matter changes of the pain matrix in patients with burning mouth syndrome.

Burning mouth syndrome (BMS) is characterized by a burning sensation in the mouth, usually in the absence of clinical and laboratory findings. Latest findings indicate that BMS could result from neuropathic trigeminal conditions. While many investigations have focused on the periphery, very few have examined possible central dysfunctions. To highlight changes of the central system of subjects with BMS, we analysed the grey matter concentration in 12 subjects using voxel-based morphometry. Data were compared with a control group (Ct). To better understand the brain mechanisms underlying BMS, the grey matter concentration of patients was also compared with those of dysgeusic patients (Dys). Dysgeusia is another oral dysfunction condition, characterized by a distorted sense of taste and accompanied by a reduced taste function. We found that a major part of the 'pain matrix' presented modifications of the grey matter concentration in subjects with BMS. Six regions out of eight were affected [anterior and posterior cingulate gyrus, lobules of the cerebellum, insula/frontal operculum, inferior temporal area, primary motor cortex, dorsolateral pre-frontal cortex (DLPFC)]. In the anterior cingulate gyrus, the lobules of the cerebellum, the inferior temporal lobe and the DLPFC, pain intensity correlated with grey matter concentration. Dys also presented changes in grey matter concentration but in different areas of the brain. Our results suggest that a deficiency in the control of pain could in part be a cause of BMS and that BMS and dysgeusia conditions are not linked to similar structural changes in the brain.

TMJ Changes in Adolescent TMD Patients Seen on MRI in Clinical Setting.

UNLABELLED: To determine whether temporomandibular joint (TMJ) changes are similar between adolescent and older TMJ disorder (TMD) patients, a retrospective chart review for TMJ MRIs was done for disc and bone changes. Patients were divided into adolescent, adult and elderly groups. RESULTS: The groups had similar prevalence of joint changes and number of joints involved. Disc changes were more prevalent in adolescents (p = 0.008), while bone changes were more prevalent in the elderly group (p = 0.10). Anterior disc displacement was the most common finding and was most prevalent in adolescents (p < 0.001). CONCLUSION: Adolescents display similar disc/bone changes in their TMJ as older TMD patients.

Caries prevention for patients with dry mouth.

Patients with xerostomia, or dry mouth, resulting from various causes, are at higher risk for developing caries because of a loss of saliva and its benefits. A loss of saliva increases the acidity of the mouth, which affects many factors that contribute to the development of caries, such as proliferation of acid-producing bacteria, inability to buffer the acid produced by bacteria or from ingested foods, loss of minerals from tooth surfaces and inability to replenish the lost minerals, and loss of lubrication. Currently, a number of new products that can substitute for these functions of saliva or induce production of saliva are available in Canada. Some of these products are reviewed and a protocol for caries prevention in this high-risk population is proposed.

Pain reduction in burning mouth syndrome (BMS) may be associated with selective improvement of taste: a retrospective study.

OBJECTIVE: The aim of this study was to examine taste function in patients who reported improvement in their pain level after treatment to determine if pain reduction is associated with change in taste function in patients with burning mouth syndrome (BMS). STUDY DESIGN: This retrospective study of patients with BMS was conducted at a private oral medicine clinic. RESULTS: Thirty-nine patients with BMS (31 females and 8 males; mean age 56.1 ± 9.4 years) reported improvement in their pain in 1 to 22 months after the initial visit (mean 5.13 ± 4.18). The most commonly used medication was clonazepam 0.25 to 0.5 mg/day. Twenty-eight patients were treated with a combination of medications. "Salt" and "bitter" responses at the fungiform papillae were increased after treatment (P = .026 and P = .044, respectively). "Salt" responses at the circumvallate papillae also increased (P < .001). Pain reduction was significant after treatment in the morning (P = .002) and in the evening (P < .001). CONCLUSIONS: Treatment of BMS can significantly decrease pain symptoms, resulting in improvement in taste function. Pain reduction often requires a combination of medications.

Taste and Pain Response in Burning Mouth Syndrome With and Without Geographic Tongue.

AIMS: To assess the effect of geographic tongue (GT) on taste, salivary flow, and pain characteristics in burning mouth syndrome (BMS) to determine whether GT is a contributing factor to BMS and whether BMS and GT represent similar patient populations. METHODS: A retrospective chart study was conducted. Patients with a diagnosis of BMS or BMS/GT were included. Data regarding smell testing, spatial taste-testing, salivary flow, oral pH, and subjective pain rating on a generalized labeled magnitude scale (gLMS) were collected. RESULTS: No significant differences in age, gender, oral pH, smell, or pain were found between groups. Stimulated and unstimulated salivary flow were significantly lower in BMS/GT. Taste responses to all taste stimuli and to ethanol were significantly lower in BMS, with the exception of sour at the fungiform papillae. CONCLUSION: BMS and BMS/GT present with similar clinical pain phenotype and demographics; however, taste was more intact in BMS/GT, suggesting that GT may be a contributing factor in the development of BMS through a mechanism that does not involve taste.

Advanced Ultrasound Screening for Temporomandibular Joint (TMJ) Internal Derangement.

PURPOSE: To present an advanced ultrasound (US) technique and propose its use as a screening diagnostic tool for temporomandibular joint (TMJ) internal derangement. MATERIALS AND METHODS: The technique is based on maintaining the US probe parallel to the articular disc, rather than traditional axial and coronal views, with the position described relative to a clock face. Validation was achieved by direct comparison with magnetic resonance imaging (MRI). A total of 61 patients, with age ranging from 13 to 67 years, were prescreened for TMJ pain and internal derangement, underwent US imaging for screening, and MRI evaluation for final diagnosis. RESULTS: 29 of the 61 patients had disc pathology on MRI. US screening produced no false positive results and only 6 false negative results, corresponding to a sensitivity of 79% and specificity of 100%. Half of the false negative cases involved disc pathology with a medial component to the disc displacement. CONCLUSION: US is both a sensitive and a specific screening tool for TMJ dysfunction when used by an appropriately trained operator, with the exception of medially displaced discs. If TMJ assessment is found to be abnormal, the patient should be referred for MRI, and any patient scheduled for surgery must have the diagnosis confirmed by MRI. If a component of medial disc displacement is suspected, MRI should be performed despite a normal screening US.

From the Cover: Drug-Induced Taste Disorders in Clinical Practice and Preclinical Safety Evaluation.

More than 200 medications can induce taste disorders in patients. They not only reduce quality of life for those affected, but can lead to malnutrition, severe dehydration and difficulty in maintaining a therapeutic regimen. Nevertheless, the impact of drug candidates on taste is rarely evaluated in preclinical toxicology studies during the early stage of drug development. Moreover, knowledge about how to investigate these adverse effects is scarce in the toxicology field. Here, we discuss the clinical status of drug-induced taste disorders in patients, with the goal of providing toxicologists with a broad understanding of its prevalence, and how stressful and even dangerous it can be to affected patients. Because taste, smell, and oral trigeminal sensation are highly interdependent, we also address drug-induced changes in olfactory and oral somatosensory perceptions. We then review the biology of the gustatory system (including anatomy and histology), and the latest developments about how taste contributes to flavor perception. Finally, we feature recently optimized preclinical approaches to investigate drug-induced taste change in animal models, including morphological evaluation of taste buds and taste cells, gustatory nerve recording, and behavioral testing. Our goals are to raise awareness of drug-induced taste disorders among toxicologists, share an overview of new approaches and key studies that can be used to identify drug-induced gustatory system toxicity early in the drug development process, and to stimulate further research at this emerging interface of chemosensory disorders with toxicology.

Geographic tongue: assessment of peripheral nerve status, Langerhans cell, and HLA-DR expression.

OBJECTIVES: The objectives of this study were to determine whether geographic tongue (GT) is an antigen-driven condition by assessing Langerhans cell numbers and the expression of human leukocyte antigen (HLA)-DP, -DQ, and -DR in the epithelium of GT and to assess peripheral nerve status for any possible damage/injury association by quantifying neurite area in connective tissue in GT. STUDY DESIGN: Randomly selected samples of GT were examined by using routine immunoperoxidase staining methods to S100 protein, neurofilament, CD1a, and HLA class II. The Student t test and Mann-Whitney U test were used to assess statistical significance. RESULTS: Langerhans cell numbers were found to be increased in GT. HLA expression was also seen in Langerhans cells and inflammatory cells and in the spinous layer and parabasal epithelial cells in 2 samples of GT. Total nerve tissue, based on area measurements, was not significantly different between GT and control tissues. CONCLUSIONS: The increase in Langerhans cells suggests that GT is a condition that is likely driven by an unknown external antigen. Peripheral nerve damage was not apparent, suggesting that this is not a mechanism whereby patients with GT become symptomatic.

Burning Mouth Syndrome.

Burning mouth syndrome (BMS) is an enigmatic, misunderstood, and under-recognized painful condition. Symptoms associated with BMS can be varied, thereby providing a challenge for practitioners and having a negative impact on oral health-related quality of life for patients. Management also remains a challenge for practitioners because it is currently only targeted for symptom relief without a definitive cure. There is an urgent need for further investigations to determine the efficacy of different therapies because this is the only way viable therapeutic options can be established for patients with this chronic and painful syndrome.

Applicability of the McGill Pain Questionnaire to the differentiation of 'toothache' pain.

The McGill Pain Questionnaire (MPQ) was administered to 102 'toothache' patients to determine whether it was sufficiently sensitive to distinguish between dental patients whose pain was clinically diagnosed as originating from a reversibly inflamed tooth pulp (group I) and those whose pain was diagnosed as originating from an irreversibly inflamed or necrotic pulp (group II). Scores for Total Pain Rank Index (PRI(T)), Sensory Pain Rank Index (PRI(S)), Evaluative Pain Rank Index (PRI(E)), Miscellaneous Pain Rank Index (PRI(M)), and Number of Words Chosen (NWC) were significantly higher (p less than 0.05) for group II patients. The PRI differences between both groups were attributed mainly to the more frequent selection by group II patients of 8 of the 20 subclasses of words and/or of words with higher rank values within the 8 subclasses. A significantly greater degree of sleep disturbance, nausea, headache, drowsiness and/or dizziness was also found in group II patients. Discriminant analysis using the 20 subclasses and 4 supplementary questions related to sleep disturbance, changes in food intake or activity levels, and accompanying symptoms, indicated that the MPQ, when used alone, correctly predicted diagnosis and treatment outcome in 73% of patients. Therefore, our findings indicate that the MPQ can distinguish between the two types of toothache and suggest that, especially when used along with other standard diagnostic tests, it may be a useful clinical adjunct in the diagnosis of dental pain.

Pain and personality profiles in burning mouth syndrome.

The McGill Pain Questionnaire (MPQ) and the Minnesota Multiphasic Personality Inventory (MMPI) were administered to 72 subjects with burning mouth syndrome (BMS) who were also requested to match the levels of their clinical pain to line lengths on a visual analogue scale (VAS) and to experimentally induced warm and painful thermal stimuli. The responses of 102 toothache pain subjects and 43 asymptomatic age- and sex-matched control subjects were used to compare the responses of the BMS subjects on the MPQ and MMPI, respectively. The results indicated that BMS pain is quantitatively similar to, but qualitatively different from, toothache pain, that self-reports of BMS pain appear to be valid, that when compared to the asymptomatic control subjects, BMS subjects show elevations in certain personality characteristics which are similar to those seen in other chronic pain patients, and that these personality disturbances tend to increase with increased pain. Therefore, our findings indicate that the pain of BMS is more severe than has previously been suggested and that the severity of this pain may explain some of the personality changes which occur in the BMS subjects.

Psychophysical assessment of tactile, pain and thermal sensory functions in burning mouth syndrome.

Tactile, two-point discrimination, thermal change detection and heat pain thresholds as well as oral stereognostic ability, warmth scaling and heat pain tolerance were compared in a group of 72 subjects with burning mouth syndrome (BMS) and 43 age- and sex-matched control subjects. No differences were found between the BMS and control subjects for any of the sensory modalities tested except for heat pain tolerance. Pain tolerance was significantly decreased for the BMS subjects at the tongue tip, a site of clinical pain in approximately 85% of the subjects tested in this study, but not at the cutaneous lower lip which was a site of pain only in approximately 17% of the subjects tested in this study. In addition, no differences in heat pain tolerance were found at the cutaneous lower lip between the control subjects and the BMS subjects who reported pain on the mucosal lower lip (approximately 49% of subjects), but heat pain tolerance was significantly decreased at this site for those BMS subjects tested without pain on the mucosal lower lip (approximately 51% of subjects). These findings do not suggest a psychogenic origin for the alteration of heat pain tolerance in the BMS subjects, but suggest instead specific changes in their peripheral or central sensory functions.

Burning mouth syndrome and other oral sensory disorders: a unifying hypothesis.

Burning Mouth Syndrome (BMS) is a sensory disorder which results in constant, bilateral burning pain of the tongue, lips, and other oral mucous membranes. Atypical odontalgia (AO) is another sensory disorder, usually defined as a toothache-like pain for which no dental cause can be identified. Previous literature has suggested that AO is often associated with a concomitant temporomandibular disorder (TMD). This hypothesis paper explores the possibility that BMS, AO and TMD can be related through hyperactivity of both the sensory and motor components of the trigeminal nerve following loss of central inhibition as a result of taste damage in the chorda tympani and/or the glossopharyngeal nerves.

Burning mouth syndrome: patch test results from a large case series.

BACKGROUND: Burning mouth syndrome (BMS) is a burning or sore mouth in the absence of changes in the oral mucosa. It is often difficult to diagnose and treat. Numerous theories of the etiology have been suggested, including contact allergy. OBJECTIVE: To determine the clinical utility of patch testing in patients with BMS. METHODS: We retrospectively reviewed the charts of patients diagnosed with BMS who had patch testing performed between January 1, 2008, and July 31, 2012. RESULTS: Of 142 consecutive patients with BMS, 132 consented to patch testing; 89 (67%) had allergic patch test reactions. Of the patients with positive results, 66 (74%) had results that were deemed to have possible relevance. The most common allergens detected were nickel sulfate 2.5%, dodecyl gallate 0.3%, octyl gallate 0.3%, fragrance mix 8%, benzoyl peroxide 1%, and cinnamic alcohol 1%. CONCLUSIONS: Our findings suggest that contact allergy may be an etiologic factor in some patients with BMS. Patch testing is a useful investigation for BMS patients.

Taste disorders: a review.

Taste disorders are distressing for patients. They can also pose a serious threat to the health of older and more vulnerable patients, who can become malnourished through a loss of taste or changes in taste perception. Despite the profound impact of taste changes on health, the literature on their diagnosis, pathogenesis and treatment is sparse. Taste changes, including the experience of unexplained foul tastes or a decrease in taste sensations, may lead patients to seek out inappropriate dental treatments, but such treatments are often unsuccessful in resolving the complaint. Correct diagnosis of taste loss is the first step in the treatment of taste abnormalities and the avoidance of unnecessary dental treatment. It is therefore helpful for both patient and health care provider to be aware of the causes of taste changes. This review presents an overview of the causes, diagnosis and management of taste abnormalities.

Increased prevalence of geographic tongue in burning mouth complaints: a retrospective study.

OBJECTIVES: The objective of this study was to assess the frequency of geographic tongue and fissured tongue (GFT) in patients with burning mouth syndrome (BMS). Our hypothesis was that benign soft tissue changes to the tongue, such as GFT, are associated with BMS. STUDY DESIGN: Retrospective review of 161 patients with BMS and 87 TMJ dysfunction cases as control. Frequency of GFT and demographics for both groups was assessed. RESULTS: In the BMS group, 26.7% of the subjects were diagnosed with GFT, whereas in the control group, 11.5% had GFT (P < .05). In the subgroup of BMS with GFT, the male-to-female ratio was approximately 1:2, whereas the male-to-female ratio of those with BMS and no GFT was approximately 1:5 (P < .05). CONCLUSIONS: Our results demonstrate a higher than expected prevalence of GFT among patients with BMS compared with a control group of patients with TMJ. In males, GFT may be a significant predictor for BMS.

A double-blind study on clonazepam in patients with burning mouth syndrome.

OBJECTIVES/HYPOTHESIS: In the treatment of burning mouth syndrome (BMS), various approaches have been tried with equivocal results. The aim of the present randomized clinical trial was to determine the efficacy of clonazepam, a GABA agonist designed as an antiepileptic drug that exerts the typical effects of benzodiazepines. STUDY DESIGN: Randomized clinical trial. METHODS: Twenty patients with idiopathic BMS were carefully selected. Clonazepam (0.5 mg/day, n = 10) or placebo (lactose, n = 10) were randomly assigned to the patients. RESULTS: Patients on clonazepam significantly improved in pain ratings (P < .001). These changes were less pronounced in the placebo group (P < .11). No significant changes were observed in a mood scale (P = .56) or for depression scores (P = .56). Taste test and salivary flow increased over sessions, but were not different between groups (P = .83 and P = .06, respectively). CONCLUSIONS: Clonazepam appears to have a positive effect on pain in BMS patients.

Results of patch testing in patients diagnosed with oral lichen planus.

BACKGROUND: Oral lichenoid lesions (OLLs) resemble oral lichen planus (OLP) but develop secondary to various underlying causes. The role of contact allergy in precipitating and/or perpetuating OLL is well documented but remains controversial. OBJECTIVE: To help elucidate the association of contact allergy and OLL, we reviewed patch-test readings in patients diagnosed with OLP-like lesions. METHODS: We retrospectively reviewed patients diagnosed with OLP-like lesions who had patch tests performed between January 1, 2006, and December 31, 2007. RESULTS: Patch tests were performed on 24 patients with a histopathologic and/or clinical diagnosis of OLP. Of these, 16 (67%) had positive patch-test readings. At least eight (50%) of these patients had clinically relevant reactions. Ten of the 16 patients (63%) had reactions to metals. In most of these patients, troublesome areas tended to localize adjacent to metallic dental restorations. Of the nine patients (56%) who had reactions to fragrances, flavorings, gallates, and/or diallyl disulfide, the majority improved after avoiding these allergens. CONCLUSION: Our findings support the notion that contact allergy may underlie the pathogenesis of OLL and that allergen avoidance may result in amelioration of disease.