Original Article Braz J Oral Sci. April/June 2009 - Volume 8, Number 2 Burning mouth syndrome: a discussion about possible etiological factors and treatment modalities Paula Aparecida Nakazone1, Andressa Vilas Boas Nogueira2, Francisco Guedes Pereira de Alencar Júnior3, Elaine Maria Sgavioli Massucato4 1 DDS, MS, Post-graduate student, Department of Restorative Dentistry, Faculdade de Odontologia de Araraquara, Universidade Estadual Paulista “Júlio de Mesquita Filho” (Unesp), Araraquara (SP), Brazil 2 DDS, MS, Post-graduate student, Department of Diagnosis and Surgery, Faculdade de Odontologia de Araraquara, Unesp, Araraquara (SP), Brazil 3 DDS, MS, PhD, Assistant Professor, Department of General Dental Sciences, Marquette University School of Dentistry, Milwaukee, Wisconsin, USA 4 DDS, MS, PhD, Assistant Professor, Department of Diagnosis and Surgery, Faculdade de Odontologia de Araraquara, Unesp, Araraquara (SP), Brazil Received for publication: April 3, 2009 Accepted: May 18, 2009 Correspondence to: Elaine Maria Sgavioli Massucato Departamento de Diagnóstico e Cirurgia, Faculdade de Odontologia de Araraquara, Universidade Estadual Paulista Rua Humaitá, 1.680, 2º andar CEP 14801-903 – Araraquara (SP), Brazil E-mail: emassucato@yahoo.com.br Abstract Although several studies discuss the contributing factors associated with the burning mouth syndrome (BMS), there is still controversy with regard to its etiology. Therefore, in the majority of cases, the establishment of an adequate diagnosis and consequently the best treatment modality is complicated. In order to assist the clinician in the estab- lishment of the correct diagnosis and management of BMS, this article reviews the literature, providing a discussion on the various etiologic factors involved in BMS, as well as the best treatment modalities for this condition that have showed to be the most effective ones in randomized clinical trials. In addition, the authors discuss some clinical char- acteristics in the differential diagnosis of BMS and other oral diseases. It is important for the clinician to understand that BMS should be diagnosed only after all other possible causes for the symptoms have been ruled out. Keywords: burning mouth syndrome, xerostomia, mouth diseases. Introduction Several diseases of the oral mucosa may have burning as a symptom, such as herpes simplex virus, oral lichen planus (under its clinical forms: erosive, atrophic and ulcerative), aphthous stomatitis, candidiasis (mainly under its acute form) and xerostomia. However, patients who refer a burning sensation if the oral mucosa or a chronic pain without any visible alteration of the oral tissues might be diagnosed as having burning mouth syndrome (BMS)1. It is very important for clinicians to be able to distinguish a burning mouth symptom caused by a specific disease besides BMS. BMS is considered to be a pain or burning sensation affecting the clinically normal oral tissues, for which local and systemic causes have been excluded. The term “syndrome”, in this case, is justified because of the simultaneous presence of several subjective symptoms, including feeling of dryness (subjective xerostomia), altered taste, and burning sensation of the oral tissues, comprising or not the tongue2,3. 63Burning mouth syndrome: a discussion about possible etiological factors and treatment modalities Braz J Oral Sci. 8(2): 62-6 Literature review Definition BMS is referred as a chronic orofacial pain or burning sensation in the oral mucosa or tissues without any clinically significant lesion or al- teration. According to the International Headache Society, BMS is an intraoral burning sensation for which no dental or medical cause is found4. The BMS pain may be described as a burning sensation that is often qualitatively compared to a toothache. A wide variety of terms have been reported in the literature to describe BMS, which include glossodynia/stomatodynia, glossopyrosis/stomatopyrosis, oral dyses- thesia and sore mouth5,6. Epidemiology BMS may occur in any tissue inside the oral cavity, although most often it is found on the two thirds of the anterior and on the tip of the tongue1. This disease has a prevalence that varies from 0.7 to 15% in the general population7-10 and has an average duration of two to three years11. It predominantly affects middle-aged women in the post- menopausal phase and in a ratio of 7:1 when compared to men12,13. Few studies have mentioned the presence of BMS in earlier ages7,12,14, which indicates that its prevalence increases with age4. According to Lamey and Lamb15, the symptomatology associated with BMS may be classified in three types16,17, as shown in Table 1. Pathogenesis and etiology The pathogenesis and etiology of the BMS are not completely under- stood yet. Some authors have suggested that there is a multifactorial etiology: local, systemic and psychological factors (Table 2)14,18-24. The local factors may include temporomandibular disorders (TMD), oral candidiasis, parafunctional habits (clenching and bruxism), xerosto- mia (Figure 1), salivary glands dysfunction, hypersensitivity reac- tions (Figure 2) and misfited and poorly designed dentures. How- ever, the literature is sometimes conflicting and unclear, because the diagnosis of BMS should be confirmed after ruling out other causes to the burning sensation, such as oral candidiasis or TMD. Special attention must be given to the dentures, since it has been demonstrated that there is a possible correlation between the prob- lems related to oral dentures (adjustment, design) and the BMS for both may cause central and/or peripheral changes in the sensory nerve function, causing atypical oral pains25,26. Types BMS symptomatology according to Lamey and Lamb15 Factors associated with BMS in each type16,17 1 Symptoms are not present when the patient wakes up, but they will appear and increase during the day. Moderate anxiety disorders. 2 Symptoms are present all day and night and strongly associated with anxiety. Severe psychiatric disorders. 3 Symptoms are not present during some days and are associated with emotional instability or a hypersensitivity reaction to some foods. Emotional instability or allergic reactions. Table 1. Classification of the symptomatology associated with burning mouth syndrome (BMS) Local Systemic Psychological Neuropathic Temporomandibular disorders Nutritional deficiencies Depression Neurogenic abnormalities Oral candidiasis Diabetes mellitus Anxiety - Parafunctional habits Hormonal disturbances Psychopathologic distress - Xerostomia Immunomediated diseases - - Salivary glands dysfunction Systemic drugs - - Hypersensitiveness reactions - - - Misfited or poorly designed dentures - - - Table 2. Factors associated with the etiology of burning mouth sensation Figure 1. Patient with xerostomia. Figure 2. Patient with hypersensitivity reaction. 64 Nakazone PA, Nogueira AVB, Alencar Júnior FGP , Massucato EMS Braz J Oral Sci. 8(2): 62-6 Concerning hypersensitivity reaction, Mott et al.26 mentioned not only allergy to denture base acrylic resins and contouring or fabrication errors, but also the presence of parafunctional habits as important factors in the development of BMS. Furthermore, Gao et al.24 have found that oral parafunctional habits are causative agents in BMS, specially tongue thrusting and lip sucking. Xerostomia has been identified in almost 65% of the patients with BMS7,14,27-29, which demonstrates that these patients are significantly more susceptible to this condition. Marques-Soares et al.30 have in- vestigated the function of the salivary gland in BMS pathogenesis and found divergent results, concluding that it is still not clear whether hyposalivation is a typical sign of this syndrome. Those authors have also evaluated the salivary flow rate and found no statistically sig- nificant differences. Furthermore, it is known that the administra- tion of certain medications as diuretics, anti-hypertensive drugs and mainly psychotropics may influence salivary gland function31. Radiotherapy on head and neck regions may produce severe and irreversible damages to the salivary glands, leading to a severe con- dition of permanent xerostomia, which have to be identified during the clinical interview32. Bergdahl and Bergdahl32 have stated that psychological factors have an influence on xerostomia, sometimes without hyposaliva- tion, and that they could be intimately related to depression, anxiety and use of antidepressants. In a case-control study that investigated anxiety and salivary cortisol levels in patients with BMS, Amenábar et al.33 found that 50% of these patients presented a worse level of anxiety than those without BMS. These authors associated this BMS- anxiety relationship with the salivary cortisol level that is presented in a higher level in patients with these two disorders. Cavalcanti et al.13 have found no difference in the presence of Can- dida albicans between BMS and control patients. Thus, candidiasis has not been confirmed as an associate etiological factor for BMS. Some systemic factors might also be associated with BMS, such as nutritional deficiencies as pernicious anaemia, iron deficiency, vitamin B complex deficiency, folate deficiency and vitamin C defi- ciency34. Yet, systemic diseases, such as diabetes mellitus, hormonal disturbs, immunomediated diseases and psychological disorders could be associated factors21,35. Some authors have pointed out a possible relationship between diabetes mellitus and BMS, since this syndrome is found in 2 to 10% of diabetic patients15,34,36,37. Although Sardella et al.38 did not find this re- lationship, burning sensation could be a symptom of an undiagnosed diabetes mellitus39 and perhaps the control of diabetes leads to the improvement or cure of BMS6. Deficiency disorders have always been referred as cause of BMS. Nutritional deficiencies have been claimed to cause BMS in 2 to 33% of patients40. However, other studies did not find a high prevalence of nutritional deficiency in patients with BMS15,36. BMS may also change the individual’s general and psychologi- cal well being, reducing the quality of life, even though it is not clear if psychopathologic distress is related to this syndrome or if it is a result of the chronic symptoms that these patients passed through18. Some studies have reported that people with BMS experience ad- verse life events more frequently than people without BMS, which may be a risk factor for developing BMS24,41. There is evidence of a possible relationship between BMS and psychogenic factors, as shown by Sardella et al.38. More recently, sev- eral authors have investigated the trigeminal somatosensory system in order to detect neurogenic abnormalities42-47. These studies sug- gest peripheral alterations in the function of this system with the presence of abnormal reflex, for example, the blink reflex44. Calcitonin gene-related peptide (CGRP) is one of the neurotransmit- ters found in the nerve fibers of the nervous system that is involved in sali- vary secretion and plays an important role in the development of pain and hyperalgesia48. Supporting this interpretation, some studies showed that the use of neuroprotective/neurotropic drugs improved the symptoms in patients with BMS19,49. However, Zidverc-Trajkovic et al.50 found no el- evated levels of CGRP in the saliva of patients with BMS, which seems to demonstrate the trigeminal nerve degeneration in this syndrome. Psychiatric disorders could be associated with more than 50% of the cases of BMS51. Several studies in psychiatric literature have as- sociated anxiety and depression with BMS symptomatology14,42,52,53. Gao et al.24 found anxiety, depression and somatization symptoms to be the most common psychological problems in BMS. Bergdahl et al.16 demonstrated that patients with BMS exhibited low levels of socialization and high levels of anxiety and health status concern when compared to a Control Group. Marques-Soares et al.30 identified medications that could have a preventive role with regard to BMS, such as systemic drugs for vascular and digestive disorders, analgesics and psychotropic drugs. Hugosson and Thorstensson53, in a study involving patients with BMS and a con- trol group, have observed that 87.5% of the patients with the syndrome were usually taking one or more drugs; 44% were psychotropic drugs, 25% were digestive disorder drugs, 25% were respiratory disorder drugs and 6.2% were vitamins54. According to Bergdahl and Bergdah7, the chronic use of systemic drugs may be a significant factor for BMS. In a study that investigated the clinical basis of this syndrome and a possible association with the oral carriage of Candida species, Caval- canti et al.13 found that 80.6% of the patients with BMS were chronic users of systemic drugs, among which 35.5% were benzodiazepines, 19.35% were other antidepressants and 38.7% were antihypertensive drugs. Some drugs, like antihypertensive agents, are frequently asso- ciated with the beginning of symptoms compatible with BMS. Anti- hypertensive drugs that act in the renin-agiotensin system are more frequently related to the occurrence of BMS55. According to Drage and Rogers11, over 37% of the patients exhibit more than one factor contributing to oral pain sensation (burning), which must be identified and treated. In contrast, there are cases of spontaneous remission in approximately half of patients with BMS, as reported elsewhere5,28,56. Sardella et al.38 evaluated a group of patients with BMS who received the definitive diagnosis after being submitted to a clinical examination, standard set of examinations (salivary flow rate), lab tests (complete blood cell count, blood glucose levels, serum iron level, transferrin level, serum vitamin B level and folic acid level) and isolation of Candida spe- 65Burning mouth syndrome: a discussion about possible etiological factors and treatment modalities Braz J Oral Sci. 8(2): 62-6 cies from oral mucosa scraping. Tests were performed for contact allergy as a means of excluding this possibility. After analysis and 18 months of follow-up, spontaneous remission cases occurred in the patients who had not received any type of treatment. Therefore, the findings of this study suggest that a spontaneous remission may be expected only in a small portion of patients within five years after the onset of BMS. Alcohol con- sumption and smoking must be abolished during the treatment of BMS. Treatment Bogetto et al.57, in a randomized clinical trial (RCT), compared amisul- pride, paroxetine, clordemetildiazepam and amitriptyline to a placebo and found a statistically significant reduction from baseline in BMS symptoms and depression for patients receiving 50 mg/day amisulpride. In a 60-day RCT, Femiano et al.58 compared alpha-lipoic acid to cellulose (placebo). The results showed that 97% of the patients receiving the treat- ment had some level of improvement, and only 40% of those receiving placebo had a slight improvement. In a 14-day RCT19 with six months of follow-up, clonazepam was compared to placebo. At the end of the treat- ment period, a statistically significant difference in the mean decrease in pain intensity was observed among the patients who used clonazepam. Cognitive behavioral therapy is another type of treatment that showed to be of great value in the management of BMS. Bergdahl et al.59, in a previous RCT, found a statistically significant difference in the reduction of pain intensity for those receiving this type of ther- apy in comparison to a placebo attention program immediately fol- lowing the therapy and after six months of follow-up. Oral lafutidine showed a significant effect in reducing the in- tensity of oral burning sensation and may be a viable option for the treatment of BMS60. Yamazaki et al.61 observed that the use of par- oxetine for the treatment of BMS reduced the pain in about 80% of patients with BMS with minor transient side effects. There is no consensus in the literature concerning the best treatment approach. Conservative management, such as low doses of tricyclic antidepressants, benzodiazepines or doxepins and topi- cal clonazepam or gabapentin are some options that have been evaluated32,62,63. However, Heckmann et al.64 demonstrated that gaba- pentin presents few or no effect in BMS. There is insufficient evidence to understand the real cause and to provide clear guidance for an effective treatment of BMS. Most stud- ies are small, uncontrolled investigations, and there are no reports of longitudinal cohort studies. Further research is therefore needed. The importance of assessing whether burning mouth is a symp- tom of other disease or a real distinct syndrome must be highlighted. Clinicians should identify the BMS and its situation and also be able to give a reliable explanation about this condition and its benign na- ture to the patient. Additionally, an individual approach concerning the assessment and treatment of patients with BMS is necessary. In order to reduce patient’s suffering, psychological methods may be helpful for patients to cope with BMS symptoms. Especially in clinical situations in which there is no consensus about the best treatment approach to be adopted, to be as conserva- tive as possible is a wise choice. In the authors’ experience, the use of combined treatment, such as behavioral modification and psycho- therapy associated with the use of gapapentin and/or clonazepan, has been successful. BMS could be a kind of neuropathic pain and could respond positively to treatment with gabapentin and other drugs used to manage this condition. Definitive diagnosis of BMS must be preceded by a thorough clin- ical examination focusing on the presence of signs such as erythema, candidiasis, xerostomia or any mucosa abnormalities, in addition to review of medical history in a detailed clinical interview. The BMS diagnosis will be defined only after excluding all possibilities of oral mucosa diseases, contact allergy reactions and all other possible causes of referred pain or burning sensation. Special attention must be given to the prescription of drugs to these patients because most medication can induce xerostomia, which may aggravate BMS. Due to the multifactorial etiology of this condition (local, systemic, psy- chogenic and neuropathic), clinicians should better opt for an inte- grated treatment adequately carried out by a multiprofessional team in order to manage all symptoms and alterations related to BMS. Furthermore, it is important to have in mind that, in most patients, the disease is self-limiting, not exceeding three years, regardless of the treatment modality used. References 1. Evans RW, Drage LA. Burning Mouth Syndrome. Headache. 2005;45:1079-81. 2. Grushka M, Epstein JB, Gorsky M. Burning Mouth Syndrome. Am Fam Physician. 2002;65:615-20. 3. Zakrzewska JM, Forssell H, Glenny AM. Interventions for the treatment of burning mouth syndrome. Cochrane Database of Systematic Reviews. 2005; Issue 1. Art. No.: CD002779. DOI: 10.1002/14651858.CD002779.pub2. 4. Headache Classification Subcommittee of the International Headache Society. The international classification of headache disorders: 2nd edition. Cephalalgia. 2004;24(Suppl 1):9-160. 5. Danhauer SC, Miller CS, Rhodus NL, Carlson CR. Impact of criteria-based diagnosis of Burning Mouth Syndrome on treatment outcome. J Orofac Pain. 2002;16:305-11. 6. Maltsman-Tseikhin A, Moricca P, Niv D. Burning mouth syndrome: will better understanding yield better management? Pain Practice. 2007;7:151-62. 7. Bergdahl M, Bergdahl J. Burning Mouth Syndrome: prevalence and associated factors. J Oral Pathol Med. 1999;28:350-4. 8. Savage NW, Vucicevic-Boras V, Barker K. Burning mouth syndrome: clinical presentation, diagnosis and treatment. Austr J Dermatol. 2006;47:77-85. 9. Lipton JA, Ship JA, Larach-Robinson D. Estimated prevalence and distribution of reports orofacial pain in the United States. J Am Dent Assoc. 1993;124:115-21. 10. Tammiala-Salonen T, Hiidenkari K, Parvinen T. Burning mouth in a Finnish adult population. Community Dent Oral Epidemiol. 1993;21:67-71. 11. Drage LA, Rogers RS. Clinical assessment and outcome in 70 patients with complaints of burning or sore moth symptoms. Mayo Clin Proc. 1999; 74:223-8. 12. Tourne LPM, Friction JR. Burning Mouth Syndrome. Critical review and proposed clinical management. Oral Surg Oral Med Oral Pathol. 1992;74:158-67. 13. Cavalcanti DR, Birman EG, Migliari DA, Silveira FRX. Burning mouth syndrome: clinical profile of Brazilian patients and oral carriage of Candida species. Braz Dent J. 2007;18:341-45. 14. Eguía Del Valle A, Aguirre Urízar JM, Martinez-Conde R, Echebarria Goikouria MA, Sagasta Pujana O. Burning mouth syndrome in the Basque Country: a preliminary study of 30 cases. Med Oral. 2003;8:84-90. 66 Nakazone PA, Nogueira AVB, Alencar Júnior FGP , Massucato EMS Braz J Oral Sci. 8(2): 62-6 15. Lamey PJ, Lamb AB. Lip component of BMS. Oral Surg Oral Med Oral Pathol. 1994;78:590-3. 16. Bergdahl J, Anneroth G, Perris H. Personality characteristics of patients with resistant Burning Mouth Syndrome. Acta Odontol Scand. 1995;53:7-11. 17. Paterson AJ, Lamb AB, Clifford TJ, Lamey PJ. Burning Mouth Syndrome: the relation between the HAD scale and parafunctional habits. J Oral Pathol Med. 1995;24:289-92. 18. Al Qran FA. Psychological profile in Burning Mouth Syndrome. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2004;97:339-44. 19. Gremeau-Richard C, Woda A, Navez ML, Attal N, Bouhassira D, Gagnieu MC, et al. Topical clonazepan in stomadynia: a randomized placebo-controlled study. Pain. 2004;108:51-7. 20. Rojo L, Silvestre FJ, Bagán JV, De Vincent T. Prevalence of psychopathology in Burning Mouth Syndrome. A comparative study among patients with and without psychiatric disorders and controls. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1994;78:312-6. 21. Soto Araya M, Rojas Alcayaga G, Esguep A. Association between psychological disorders and presence of lichen planus, Burning Mouth Syndrome and recurrent aphtous stomatitis. Med Oral. 2004;9:1-7. 22. Velasco E, Valencia S, Blanco A, Velasco C. El síndrome de ardor bucal em el anciano. La identificación de lo transtornos psíquicos em su etiopatogenia. Ver Esp Geriatr Gerodontol. 1998;33:19-24. 23. Zilli C, Brooke RI, Lau CL, Merskey H. Screening for psychiatric illness in patients with oral dysesthesia by means of the general health questionnaire twenty eight item version (GHQ-28) and irritability, depression and anxiety scale (IDA). Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1989;67:384-9. 24. Gao J, Chen L, Zhou J, Peng J. A case-control study on etiological factors involved in patients with burning mouth syndrome. J Oral Pathol Med. 2009;38:24-8. 25. Svensson P, Kaaber S. General health factors and denture function in patients with burning mouth syndrome and matched control subjects. J Oral Rehabil. 1995;22:887-95. 26. Mott AE, Grushka M, Sessle BJ. Diagnosis and management of taste disorders and burning mouth syndrome. Dent Clin North Am. 1993;37:33-71. 27. Soares MSM, Küstner EC, Pifarrè CS, Campillo MERDR, López JL. Association of Burning Mouth Syndrome with xerostomia and medicines. Med Oral Patol Oral Cir Bucal. 2005;10:301-8. 28. Somacarrera ML, Pinos HP, Hérnandes G, Lucas ML. Síndrome de boca ardiente. Aspectos clínicos y perfil psicológico asociado. Arch Odontoestomatol. 1998;14:299-306. 29. Sreebny LM, Schwartz SS. A reference guide to drugs and dry mouth. 2nd edition. Gerodontology. 1997;14:33-47. 30. Marques-Soares M. Estudio clínico de pacientes con Síndrome de boca Ardiente: xerostomia, flujo salival, medicamentos, ansiedad y depresión. [Doctorate thesis]. Barcelona, Spain: Universidad de Barcelona; 2002. p 37-53. 31. Bergdahl J, Anneroth G. Burning mouth syndrome: literature review and model for research and management. J Oral Pathol Med. 1993;22:433-8. 32. Bergdahl M, Bergdahl J. Low unstimulated salivary flow and subjective oral dryness: association with medication, anxiety, depression, and stress. J Dent Res. 2000;79:1652-8. 33. Amenábar JM, Pawlowski J, Hilgert JB, Hugo FN, Bandeira D, Lhuller F, et al. Anxiety and salivary cortisol levels in patients with burning mouth syndrome: case-control study. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2008;105:460-5. 34. Lamey PJ, Lamb AB. Prospective study of aetiological factors II: BMS. Br Med J. 1988;296:1243-6. 35. Forssell H, Jääskelainen SH, Tenovuo O, Hinkka S. Sensory dysfunction in Burning Mouth Syndrome. Pain. 2002;99:41-7. 36. Zegarelli DJ. Burning mouth: an analysis of 57 patients. Oral Surg Oral Med Oral Pathol. 1984;58:34-8. 37. Lamey PJ. Burning mouth syndrome. Dermatol Clin. 1996;14:339-54. 38. Sardella A, Lodi G, Demarosi F, Uglietti D, Carrassi A. Causative or precipitating aspects of burning mouth syndrome: a case-control study. J Oral Pathol Med. 2006;35:466-71. 39. Gibson J, Lamey PJ, Lewis M. Oral manifestations of previously undiagnosed non- insulin dependent diabetes mellitus. J Oral Pathol Med. 1990;19:284-7. 40. Brooke RI, Segganski DP. Aetiology and investigation of the sore mouth. J Can Dent Assoc. 1977; 43: 504-6. 41. Lamey PJ, Freeman R, Eddie SA, Pankhurst C, Rees T. Vulnerability and presenting symptoms in burning mouth syndrome. Oral Surg Med Oral Pathol Oral Radiol Endod. 2005;99:48-54. 42. Gao S, Wang Y, Wang Z. Assessment of trigeminal somatosensory evoked potentials in Burning Mouth Syndrome. Chin J Dent Res. 2000;3:40-6. 43. Jääskelainen SH, Forssell H, Tenovuo O. Abnormalities of the blink reflex in Burning Mouth Syndrome. Pain. 1997;73:455-60. 44. Jääskelainen SH, Forssell H, Tenovuo O. Electrophysiological testing of the trigeminofacial system: aid in the diagnosis of atypical pain. Pain. 1999;80: 191-200. 45. Jääskelainen SH, Rinne JO, Forssell H, Tenovuo O, Kaasinen V, Sonninen P, et al. Role of the dopaminergic system in chronic pain. A fluorodopa-PET study. Pain. 2000;90:257-60. 46. Svensson P, Bjerring P, Arendt-Nielsen L, Kaaber S. Sensory and pain thresholds to orofacial argon laser stimulation in patients with burning mouth syndrome. Clin J Pain. 1993;9:207-9. 47. Femiano F, Scully C. Burning Mouth Syndrome: double-blind controlled study of alpha-lipoic acid (thiotic acid) therapy. J Oral Pathol Med. 2002;31:267-9. 48. Greco R, Tassorelli C, Sandrini G, Di Bella P, Buscone S, Nappi G. Role of calcitonin gene-related peptide and substance P in different models of pain. Cephalalgia. 2008;28:114-26. 49. Bergdahl J, Anneroth G, Perris H. Cognitive therapy in the treatment of patients with burning mouth syndrome: a controlled study. J Oral Pathol Med. 1995; 24: 213-5. 50. Zidverc-Trajkovic J, Stanimirovic D, Obrenovic R, Tajti J, Vécsei L, Gardi J, et al. Calcitonin gene-related peptide levels in saliva of patients with burning mouth syndrome. J Oral Pathol Med. 2009;38:29-33. 51. Bogetto F, Marina G, Ferro G, Carbone M, Gandolfo S. Psychiatric co morbidity in patients with Burning Mouth Syndrome. Psychosomatic Med. 1998;60: 378-85. 52. Carlson CR, Miller CS, Reid K. Psychosocial Profiles of patients with Burning Mouth Syndrome. J Orofac Pain. 2000;14:59-64. 53. Hugosson A, Thorstensson B. Vitamin B status and response to response to replacement therapy in patients with Burning Mouth Syndrome. Acta Odontol Scand. 1991;49:367-75. 54. Palacios-Sánchez MF, Jordana-Comín X, García-Sívoli CE. Burning mouth syndrome: a retrospective study of 140 cases in a sample of Catalan population. Med Oral Patol Oral Cir Bucal. 2005;10:388-93. 55. Salort-Llorca C, Minguez-Serra MP, Silvestre FJ. Drug-induced burning mouth syndrome: a new etiological diagnosis. Med Oral Patol Oral Cir Bucal. 2008;13:E167-70. 56. Gilpin SF. Glossodynia. JAMA. 1936;106:1722-4. 57. Bogetto F, Bonatto Revello R, Ferro G, Maina G, Ravizza L. Psychopharmacological treatment of burning mouth syndrome (BMS). A study on a sample of 121 patients. Minerva Psichiatrica. 1999;40:1-10. 58. Femiano F, Gombos F, Scully C, Busciolano M, De Luca P. Burning mouth syndrome (BMS): controlled open trial of the efficacy of alpha-lipoic acid (thioctic acid) on symptomatology. Oral Diseases. 2000;6:274-7. 59. Bergdahl J, Anneroth G, Perris H. Cognitive therapy in the treatment of patients with resistant burning mouth syndrome: a controlled study. J Oral Pathol Med. 1995;24:213-5. 60. Toida M, Kato K, Makita H, Long NK, Takeda T, Hatakeyama D, et al. Palliative effect of lafutidine on oral burning sensation. J Oral Pathol Med. 2009;38:262-8. 61. Yamazaki Y, Hata H, Kitamori S, Onodera M, Kitagawa Y. An open-label, noncomparative, dose escalation pilot study of the effect of paroxetine in treatment of burning mouth syndrome. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2009;107:e6-11. 62. Drage LA, Rogers RS. Burning Mouth Syndrome. Dermatol Clin. 2003;21:135-45. 63. Petruzzi M, Lauritano D, De Benedittis M, Baldoni M, Serpico R. Systemic capsaicin for Burning Mouth Syndrome: short-term results of a pilot study. J Oral Pathol Med. 2004;33:111-4. 64. Heckmann SM, Heckmann JG, Ungethum A, Hujoel P, Hummel T. Gabapentin has little or no effect in the treatment of burning mouth syndrome - results of an open-label pilot study. Eur J Neurol. 2006;13:6-7.