Salivary Alpha-Amylase Activity: A Possible Indicator of Pain-Induced Stress in Orthodontic Patientspme_

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1 Pain Medicine 2011; 12: Wiley Periodicals, Inc. Salivary Alpha-Amylase Activity: A Possible Indicator of Pain-Induced Stress in Orthodontic Patientspme_ Marcio José da Silva Campos, MSc,* Nádia Rezende Barbosa Raposo, PhD, Ana Paula Ferreira, PhD, and Robert Willer Farinazzo Vitral, PhD Departments of *Orthodontics, Food and Toxicology, Parasitology, Microbiology and Immunology and Orthodontics and Pediatrics, Juiz de Fora Federal University, Juiz de Fora, Brazil Reprint requests to: Robert Willer Farinazzo Vitral, PhD, Department of Orthodontics and Pediatrics, Juiz de Fora Federal University, Bairro Martelos Juiz de Fora, MG CEP: , Brazil. Tel: ; Fax: ; robertvitral@acessa.com. Abstract Introduction. Pain, a common experience reported by orthodontic patients, has its intensity assessed with the help of subjective scales, which have a limited and disputable value. Such unpleasant experience, which may raise stress levels, is reflected by an increase in the salivary concentration of alpha-amylase. Objective. Assess the correlation between the salivary levels of alpha-amylase and pain intensity reported by patients during orthodontic treatment. Patients. Twenty male patients (11 37 years of age) were assessed daily, before treatment, after bracket bonding, and after initial arch wire insertion. Design. Saliva was sampled for alpha-amylase analysis, and pain intensity was measured with the visual analog scale. Results. There was no correlation between alphaamylase concentrations in the saliva and pain intensity, although the patients had a significant and progressive increase of alpha-amylase levels during the assessment period. Conclusions. The findings may reflect the psychological stress caused by the presence and activation of the fixed appliance. Key Words. Orthodontic Treatment; Alpha- Amylase; Visual Analog Scale; Stress; Saliva; Pain Intensity Introduction Pain, a complex, multifaceted experience generally associated with present or potential damage, involves sensitive, emotional, cognitive, and motivational dimensions [1 3], with the result that the intensity of painful stimuli is modulated by the individual s personality [4,5]. Assessment of pain intensity is undertaken through subjective methods, such as the visual analog scale (VAS) [3,4,6 14]. Yet, instruments for subjective assessment have limited value [13], especially in science, where the need of reproducible methods demands direct and objective assessments. Salivary alpha-amylase concentrations have been used to determine pain-induced stress levels, having shown good correlation with scales for the subjective analysis of pain intensity [13,15]. This happens because the production of salivary alpha-amylase reflects the activity of the sympathetic adrenal medullary system (SAMS) in individuals under stress [13,16 19]. Subjectively assessed pain [3,4,6 14] is routinely reported by patients undergoing orthodontic treatment, being caused by force application to the teeth [4,7 10,20 22] and trauma due to attrition of brackets and wires in the oral mucosa [3,11,23 25]. The aim of this study was to assess the correlation between alpha-amylase levels in the saliva and pain intensity reported by patients after bracket bonding and after initial arch wire insertion. Methods Subjects Twenty male patients seeking orthodontic treatment were selected according to the following criteria: absence of deciduous teeth, no previous orthodontic treatment, good 1162

2 Salivary Alpha-Amylase Activity in Orthodontic Patients general health, disease-free oral mucosa, and periodontal tissue. Mean age was years (range years). Because the experience of pain is influenced by emotional, cognitive, and motivational characteristics, and also by family behavioral patterns [3,26], the following individuals were excluded from the study: dentists or dental students; close relatives or spouses of dentists or of subjects who had used a fixed appliance within the previous 12 months; those who feared dental treatment; and users of psychotropic drugs (antipsychotics, benzodiazepines, antiseizure drugs, or antidepressants), non-steroidal antiinflammatory drugs (NSAIDs), and analgesics. Procedures This study was approved by the Committee of Ethics on Research and the participants, all volunteers, signed an informed consent after receiving full explanation about the procedures. The patients were assessed during a period of 21 days, divided in three phases: pretreatment (days 1 7), bonding (days 8 14), and initial arch wire insertion (days 15 21), during which no analgesics or NSAIDs were used. In order to determine the alpha-amylase levels, saliva was sampled daily during the 21 days. Pain was also recorded daily but only during the bonding and initial arch wire insertion phases. On the morning of the 7th day, brackets and tubes (Mini Standard Edgewise American Orthodontics, Sheboygan, WI, USA) were bonded to the vestibular surfaces of the upper incisors, canines, premolars, and first molars. On the morning of the 14th day, a in. pre-formed arch (Titanium Memory Wire, , American Orthodontics) was totally inserted in the slots of all brackets and in the tubes, being then fixed with a mm steel tie wire. Alpha-amylase concentrations in the saliva samples were determined through the Salivette Cortisol device ( Sarstedt, Numbrecht, Germany), with a synthetic and neutral polyester swab. Sampling occurred on waking, before toothbrushing, drinking, or eating. The swab was kept under the tongue for 2 minutes and then transferred to the Salivette, the kit being stored in a domestic freezer for a maximum period of 48 hours, being retrieved and transported in cold boxes with ice and stored at -80 C up to the day of the analysis. Pain intensity was recorded in a form containing two 100 mm VAS [27], one for toothache (How much toothache are you feeling?) and the other for oral mucosa pain (How much pain are you feeling on the lips and cheeks?), filled in by the patients on waking. The VAS ranged from no pain to worst ever pain, and all values were determined from the distance in millimeters from the left margin of the horizontal line to the center of the marking made by the patient. The value set for the analyses of pan intensity was determined by the means of the two VASs. Alpha-Amylase Analysis All samples were diluted to 1:100 for duplicate analysis with a kinetic colorimetric method for alpha-amylase analysis kit (BioTecnics, Varginha, MG, Brazil), according to the manufacturer s instructions. Absorbance was assessed at 405 nm wavelength using a BTS-370 microtiter plate absorbance reader (BioSystems, Bucharest, Romania), with quantification through the alpha-amylase standard curve. Statistical Analysis Wilcoxon s test was used to compare the alpha-amylase concentration means between the pretreatment/bonding, pretreatment/initial arch wire insertion, and bonding/initial arch wire insertion phases. Spearman s test was used for the daily analysis of correlation between pain intensity and alpha-amylase concentration means. The Statistical Package for the Social Sciences (SPSS ; SPSS Inc., Chicago, IL, USA) was used for the analyses. Results Daily means of alpha-amylase salivary concentrations and pain intensity during the bonding and initial arch wire insertion phases are shown in Figure 1. The means of alpha-amylase concentrations in the three phases are shown in Figure 2. Alpha-amylase salivary concentrations showed a significant difference between the assessment phases (Table 1), with a progressive increase during the period. There was no significant correlation between the daily means of alpha-amylase concentrations and pain intensity, as assessed by Spearman s test (r =-0.339; P = 0.235) as shown in Figure 3. Discussion Salivary alpha-amylase is produced by the salivary glands [28] and has, as its main function, the enzymatic digestion of carbohydrates [29]. These glands have a large number of norepinephrine-stimulated beta-adrenergic receptors [28,30]. SAMS activation during psychological stress Table 1 Comparison of alpha-amylase concentrations (U/mL) between the assessment phases Z (Wilcoxon) P Value Pretreatment/bonding phases <0.05 Pretreatment/initial arch wire phases <0.05 Bonding/initial arch wire phases <

3 Campos et al. Figure 1 Salivary alpha-amylase concentration and pain intensity during the bonding (days 8 14) and initial arch wire insertion (days 15 21) phases. VAS = visual analog scale. increases plasma norepinephrine, with a consequent increase in the production and release of alpha-amylase [16 19,31,32]. Pain is recognized as a stressful agent [33] with SAMSactivating capacity [34,35], leading to an increase in the production and secretion of alpha-amylase, which makes the latter a marker of pain sensation [13,15]. In this study, patients reported pain of different intensities after insertion and activation of the fixed orthodontic appliance, in accordance with previous reports [3,4,7 11,20 25]. Yet, no correlation between the intensity of reported pain and the salivary concentrations of alpha-amylase was found, a result that differs from that obtained by Shirasaki et al. [13] and Arai et al. [15] in patients with chronic pain. The discrepancy between these two variables can be seen in Figure 1, where alpha-amylase and pain behave differently between days 8 and 21. Although alphaamylase levels in the saliva did not correlate with VASdetermined pain intensity, Shirasaki et al. [13] reported that the scale is sensitive enough to record pain-induced psychological stress. Salivary alpha-amylase concentrations increased progressively during the study period, there being a significant difference in the bonding and initial arch wire insertion phases compared with the pretreatment phase. This may have been due to the psychological stress caused by the installation of the fixed appliance or to pain anticipation by Figure 2 Salivary alphaamylase mean concentrations during pretreatment (days 1 7), bonding (days 8 14), and initial arch wire insertion (days 15 21) phases. 1164

4 Salivary Alpha-Amylase Activity in Orthodontic Patients Figure 3 Correlation between the daily means of salivary alpha-amylase concentrations and pain intensity. the patients [10,21]. Similar observations were made by Arai et al. [15], who reported a possible influence of anxiety commonly found in cancer patients on the salivary concentrations of alpha-amylase. The results indicate that analysis of alpha-amylase concentrations was not adequate to objectively determine the pain experimented by patients undergoing orthodontic treatment. Salivary alpha-amylase levels did not show a significant relationship with reported pain intensity and were not adequate to objectively determine the pain experimented by patients undergoing orthodontic treatment. Yet, the progressive concentration increase observed during the study period suggests an emotional stress overload in these patients, as a response to treatment start. References 1 International Association for the Study of Pain. Pain terms: A list with definitions and notes on usage. Pain 1979;6: Sessle BJ. The neurobiology of facial and dental pain: Present knowledge, future directions. J Dent Res 1987;66: Bergius M, Kiliaridis S, Berggren U. Pain in orthodontics: A review and discussion of the literature. J Orofac Orthop 2000;61: Jones M, Chan C. The pain and discomfort experienced during orthodontic treatment: A randomized controlled clinical trial of two initial aligning arch wires. Am J Orthod Dentofacial Orthop 1992;102: Kiliaridis S, Bergius M. Pain and discomfort in orthodontics. In: Graber TM, Eliades T, Athanasiou AE, eds. Risk Management in Orthodontics: Experts Guide to Malpractice. Chicago, IL: Quintessence Publishing; 2004: Seymour RA, Simpson JM, Charlton JE, Phillips ME. An evaluation of length and end-phrase of visual analogue scales in dental pain. Pain 1985;21: Ngan P, Kess B, Wilson S. Perception of discomfort by patients undergoing orthodontic treatment. Am J Orthod Dentofacial Orthop 1989;96: Scheurer PA, Firestone AR, Burgin WL. Perception of pain as a result of orthodontic treatment with fixed appliances. Eur J Orthod 1996;18: Fernandes LM, Øgaard B, Skoglund L. Pain and discomfort experienced after placement of a conventional or a superelastic NiTi aligning archwire. A randomized clinical trial. J Orofac Orthop 1998;59: Firestone AR, Scheurer PA, Bürgin WB. Patients anticipation of pain and pain-related side effects, and their perception of pain as a result of orthodontic treatment with fixed appliance. Eur J Orthod 1999;21: Kluemper GT, Hiser DG, Rayens MK, Jay MJ. Efficacy of a wax containing benzocaine in the relief of oral 1165

5 Campos et al. mucosal pain caused by orthodontic appliances. Am J Orthod Dentofacial Orthop 2002;122: Polat Ö, Karaman AI. Pain control during fixed orthodontic appliance therapy. Angle Orthod 2005;75: Shirasaki S, Fujii H, Takahashi M, et al. Correlation between salivary Amylase activity and pain scale in patients with chronic pain. Reg Anesth Pain Med 2007;32: Fleming PS, Dibiase AT, Sarri G, Lee RT. Pain experience during initial alignment with a self-ligating and a conventional fixed orthodontic appliance system A randomized controlled clinical trial. Angle Orthod 2009;79: Arai YC, Matsubara T, Shimo K, et al. Small correlation between salivary alpha-amylase activity and pain intensity in patients with cancer pain. Acta Anaesthesiol Scand 2009;53: Chatterton RT, Vogelsong KM, Lu YC, Ellman AB, Hudgens GA. Salivary alpha-amylase as a measure of endogenous adrenergic activity. Clin Physiol 1996;16: Rohleder N, Nater UM, Wolf JM, Ehlert U, Kirschbaum C. Psychosocial stress-induced activation of salivary alpha-amylase: An indicator of sympathetic activity? Ann N Y Acad Sci 2004;1032: Nater UM, Rohlederb N, Gaaba J, et al. Human salivary alpha-amylase reactivity in a psychosocial stress paradigm. Int J Psychophysiol 2005;55: Nater UM, La Marca R, Florin L, et al. Stress-induced changes in human salivary alpha-amylase activity Associations with adrenergic activity. Psychoneuroendocrinology 2006;31: Jones ML. An investigation into the initial discomfort caused by placement of an archwire. Eur J Orthod 1984;6: Oliver RG, Knapman YM. Attitudes to orthodontic treatment. Br J Orthod 1985;12: Brown DF, Moerenhout RG. The pain experience and psychological adjustment to orthodontic treatment of preadolescents, adolescents, and adults. Am J Orthod Dentofacial Orthop 1991;100: Kvam E, Gjerdet NR, Bondevik O. Traumatic ulcers and pain during orthodontic treatment. Community Dent Oral Epidemiol 1987;15: Kvam E, Bondevik O, Gjerdet NR. Traumatic ulcers and pain in adults during orthodontic treatment. Community Dent Oral Epidemiol 1989;17: Pereira BR, Tanaka OM, Lima AAS, et al. Metal and ceramic bracket effects on human buccal mucosa epithelial cells. Angle Orthod 2009;79: Krishnan V. Orthodontic pain: From causes to management A review. Eur J Orthod 2007;29: Huskisson EC. Measurement of pain. Lancet 1974;9: Baum BJ. Principles of salivary secretion. Ann N Y Acad Sci 1993;694: Bosch JA, Geus JC, Veerman ECI, Hoogstraten J, Amerongen AVN. Innate secretory immunity in response to laboratory stressors that evoke distinct patterns of cardiac autonomic activity. Psychosom Med 2003;65: Turner RJ, Sugiya H. Understanding salivary fluid and protein secretion. Oral Dis 2002;8: Takai N, Yamaguchi M, Aragaki T, et al. Effect of psychological stress on the salivary cortisol and amylase levels in healthy young adults. Arch Oral Biol 2004;49: Gordis EB, Granger DA, Susman EJ, Trickett PK. Asymmetry between salivary cortisol and alphaamylase reactivity to stress: Relation to aggressive behavior in adolescents. Psychoneuroendocrinology 2006;31: Sved AF, Cano G, Passerin AM, Rabin BS. The locus coeruleus, Barrington s nucleus, and neural circuits of stress. Physiol Behav 2002;77: Drummond PD. Involvement of the sympathetic nervous system in complex regional pain syndrome. Int J Low Extrem Wounds 2004;3: Janig W. The sympathetic nervous system in pain. Eur J Anaesthesiol 1995;10: