- Email: [email protected]
Effectiveness of binaural beats in reducing preoperative dental anxiety
YBJOM-5129; No. of Pages 4
ARTICLE IN PRESS Available online at www.sciencedirect.com
ScienceDirect British Journal of Oral and Maxillofacial Surgery xxx (2017) xxx–xxx
Effectiveness of binaural beats in reducing preoperative dental anxiety B.K. Isik a,∗ , A. Esen a , B. Büyükerkmen b , A. Kilinc¸ a , D. Menziletoglu a a b
Necmettin Erbakan University, Faculty of Dentistry, Oral and Maxillofacial Surgery Department, Konya, Turkey Necmettin Erbakan University, Faculty of Dentistry, Prosthodontics Department, Konya, Turkey
Accepted 26 February 2017
Abstract Binaural beats are an auditory illusion perceived when two different pure-tone sine waves are presented one to each ear at a steady intensity and frequency. We evaluated their effectiveness in reducing preoperative anxiety in dentistry. Sixty patients (30 in each group) who were to have impacted third molars removed were studied (experimental group: 20 women and 10 men, mean (range) age 24 (18-35) years, and control group: 22 women and 8 men, mean (range) age 28 (15-47) years). All patients were fully informed about the operation preoperatively, and their anxiety recorded on a visual analogue scale (VAS). The local anaesthetic was given and the patients waited for 10 minutes, during which those in the experimental group were asked to listen to binaural beats through stereo earphones (200 Hz for the left ear and 209.3 Hz for the right ear). No special treatment was given to the control group. In both groups anxiety was then recorded again, and the tooth removed in the usual way. The paired t test and t test were used to assess the significance of differences between groups. The degree of anxiety in the control group was unchanged after the second measurement (p = 0.625), while that in the experimental group showed a significant reduction in anxiety (p = 0.001). We conclude that binaural beats may be useful in reducing preoperative anxiety in dentistry. © 2017 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Keywords: Binaural beats; anxiety; dental anxiety; preoperative anxiety; dental fear; oral surgery
Introduction Anxiety is an emotional state that precedes a threatening encounter, which sometimes is not even identifiable,1 and is common both for dental patients and professionals. It can prevent patients making regular visits to the dentist, and it has the potential to affect their quality of life.2,3 It can evoke physical, cognitive, emotional, and behavioural responses, and managing such patients is stressful for many dentists.4 Because anxiety is often closely linked to painful stimuli and increased perception of pain, affected patients experience
∗ Corresponding author at: Necmettin Erbakan Üniversitesi, Dis Hekimligi Fakültesi, Konya, Turkey. Tel.: +90 332 220 00 25, Fax: +90 332 220 00 45. E-mail address: [email protected] (B.K. Isik).
more pain that lasts longer, and they need more analgesics.1,5 Psychotherapeutic or pharmacological interventions, or both, have been suggested to deal with it.1 Binaural beats occur when two sounds with steady intensities but different frequencies are presented separately, one to each ear. The resulting perception is of a single tone with a frequency that is midway between the two carrier tones and that waxes and wanes in amplitudes at a rate equal to the difference between them. They require the combined action of both ears.6 Their use is not new and much research has been done,7 but we know of no report of their use in dental anxiety. In this prospective randomised clinical study we investigated the efficacy of binaural beats on anxiety among patients about to have impacted third molars removed.
http://dx.doi.org/10.1016/j.bjoms.2017.02.014 0266-4356/© 2017 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Please cite this article in press as: Isik BK, et al. Effectiveness of binaural beats in reducing preoperative dental anxiety. Br J Oral Maxillofac Surg (2017), http://dx.doi.org/10.1016/j.bjoms.2017.02.014
YBJOM-5129; No. of Pages 4
2
ARTICLE IN PRESS B.K. Isik et al. / British Journal of Oral and Maxillofacial Surgery xxx (2017) xxx–xxx
Patients and method The study was approved by the local ethics committee (approval number 41980859/050.01). Inclusion criteria were having a fully impacted mandibular third molar tooth that required removal, and being otherwise healthy. Patients who had psychiatric or hearing disorders or epilepsy, or who were taking antidepressants, anticonvulsants, or opioids, were excluded. We included 60 volunteers who were randomly divided into experimental and control groups (n = 30 in each). There were 20 women and 10 men in the experimental group, whose mean (range) age was 24 (18-35) years, and 22 women and 8 men in the control group, whose mean (range) age was 28 (15-47) years. Randomisation was by the toss of a coin. Before the operations all patients were told that they had an impacted tooth that needed to be removed. The operation was outlined (without getting graphic), and it was explained that postoperatively they could expect some pain, swelling, and temporary inability to open the mouth completely. They then recorded their degree of anxiety on a visual analogue scale (VAS), which has previously been shown to be a valid way in which to evaluate dental anxiety.8–10 This scale comprised a 100 mm horizontal line drawn on paper, the left-hand end of which was marked “no anxiety at all”, and the right-hand end “worst anxiety imaginable”. There were no other expressions or numbers on the line. Patients were asked to make a mark that indicated their degree of anxiety on the line, which was measured (mm) from the left-hand end. This record was labelled “first measurement”. In the control group, the local anaesthetic was given, and they waited for 10 minutes. During this period, nothing was done, there was no background music or noise, and we did not talk to the patient about the operation. The operating room and table was prepared in the usual way. After the 10 minute’ period was over, patients’ anxiety was recorded again. This was labelled “second measurement”. In the experimental group the local anaesthetic was given and the patient was asked to listen to binaural beats through stereo earphones (200 Hz for the left ear and 209.3 Hz for the right ear). The frequencies were produced by software (Brain Waves Binaural Beats, MynioTech Apps, Chapeco, Santa Catarina, Brazil) running on a mobile device (Samsung Galaxy S II, Samsung Electronics Co Ltd, South Korea). The patients were allowed to adjust the volume as they wished. The binaural beats that we used were “pure” frequencies: that is, there was no background music or another soothing sound such as rain drops or waves. After the patient had listened to 10 minutes of binaural beats, the earphones were taken off and the anxiety recorded again. This was labelled “second measurement” in the experimental group. All patients were instructed not to close their eyes during the waiting period, as this could affect the natural brainwaves and interfere with our results. The operations were then con-
Table 1 Mean (SD) first and second visual analogue scores for anxiety in experimental and control groups (n = 30 in each). Measurement
Experimental
Control
First Second p value
5.37 (2.12) 3.59 (2.23) <0.01
5.52 (2.42) 5.39 (2.65) 0.625
tinued in the usual way. The type of incision, volume, and type of local anaesthetic were the same in both groups. Statistical analysis We used SigmaPlot 12.5 (Systat Software Inc, San Jose, CA, USA) for statistical analyses. The data were tested for normality with the Shapiro-Wilk test. The data satisfied the requirements for parametric tests, so the significance of differences between the groups was assessed with the aid of the paired t test and intergroup comparisons were assessed with the t test. Probabilities of 0.05 or less were accepted as significant.
Results At the first measurement there was no significant difference (p = 0.402) between the anxiety felt in the experimental and control groups (t = −0,250, df 58; 95% CI of the difference between means −1.323 to 1.030; difference = −0.147). At the second measurement the difference between the two groups was significant (p = 0.006), the experimental group having less anxiety (Table 1) (t = −2.843, df 58; 95% CI −3.061 to −0.532; difference = −1.797). As we could find no similar report elsewhere we considered our research as a pilot study and made a post hoc power analysis, which showed a power of 0.88 at an ␣ of 0.05. On within-group analyses there was a significant decrease (p < 0.001) in anxiety in the experimental group (t = 7.258, df 29; 95% CI for difference of means 1.278 to 2.282; difference between means = 1.780). However, in the control group there was no significant difference (p = 0.625) between the first and second measurements (t = 0.494, df 29; 95% CI for difference of means −0.408 to 0.668; difference between means = 0.130).
Discussion Treating an anxious patient is stressful. Cooperation is poor, treatment takes longer, and it is likely to be an unpleasant experience for both patient and dentist.4 The physiological effects may include feelings of exhaustion after a visit to the dentist, while the cognitive impact can involve unhelpful thoughts, beliefs, and fears, together with avoidance and other behaviour related to eating and oral hygiene. Disturbances of sleep and social interactions,
Please cite this article in press as: Isik BK, et al. Effectiveness of binaural beats in reducing preoperative dental anxiety. Br J Oral Maxillofac Surg (2017), http://dx.doi.org/10.1016/j.bjoms.2017.02.014
YBJOM-5129; No. of Pages 4
ARTICLE IN PRESS B.K. Isik et al. / British Journal of Oral and Maxillofacial Surgery xxx (2017) xxx–xxx
and feelings of low self-esteem and self-confidence, have also been reported.11 Dental anxiety can also discourage the patient from future visits.1 There is no single, universally effective management for dental anxiety. Drugs have been used to achieve sedation, as has general anaesthesia. In a sedated state, pulmonary and cardiovascular functions are not affected but cognitive function and physical coordination are reduced. The use of general anaesthesia is obviously reserved for more challenging cases such as severe anxiety, phobia, and psychiatric disorders.1 Psychotherapeutic interventions have also been tried. Indeed, cognitive behaviour therapy has been highly successful.1 Binaural beats were first reported in the nineteenth century and described in detail by Oster in 1973.6 The theory behind them is to present a sound with a steady intensity and frequency to one ear and another sound with the same intensity but slightly different frequency to the other ear. As a result the brain produces pulsations in the amplitude and localisation that is the same with the perceived sounds. These pulsations are known as “binaural beats” or “binaural tones”.7 It has been suggested that tones with a frequency from 200 to 900 Hz are more effective in provoking binaural beats than those that exceed 1000 Hz.12,13 The difference in frequency between the two sounds must be less than 30 Hz for the beats to occur, otherwise the two tones are captured independently, and no beats are perceived.7 Many studies have reported the psychological and physiological effects of binaural beats. For example, treatment of chronic pain,14 improving the quality of sleep,15 improving vigilance,16 and decreasing preoperative anxiety.17 There is, however, no agreement about the mechanism of binaural beats. The basic hypothesis is that the human brain alters its dominant EEG frequency towards the frequency of external stimuli to synchronise neural activity with stimuli from binaural beats.7 However, some authors disagree with this explanation, and have reported no significant differences in cortical frequency during the period of stimulation with binaural beats compared with a white noise signal.18,19 VAS is known to be valid for evaluating dental anxiety,8–10 and a VAS of 4.8 or more indicates dental anxiety.8 In our study, mean anxiety scores were 5.37 for the experimental group and 5.52 for the control group on the first measurement. We may therefore surmise that both groups had dental anxiety when they entered the operating theatre. At the second measurement, we found the anxiety scores 3.59 for the experimental group and 5.39 for the control group, which suggests that the use of binaural beats reduced anxiety, while merely waiting in the operating theatre was ineffective. Because we could find no previous studies about the use of binaural beats in dental publications, we had no guidelines for calculating the frequency and duration of the binaural beats. We chose the frequency (9.3 Hz) from the ␣ band to produce a relaxing effect. A duration of 10 minutes was set empirically, as it was considered to be long enough to see the effect of the local anaesthetic solution and short enough
3
to be used in a routine clinical environment. It is possible to change these variables and test the outcomes. Dentists can easily use binaural beats to decrease preoperative anxiety. There are numerous computer programs that can produce them for all major operating systems and many of them are free. A personal computer, a tablet, or a smartphone (already available in most dental surgeries) can therefore be used. There are even pre-recorded binaural beats that can be downloaded from the internet and listened to with a music player. Age can limit the effect of binaural beats. It is common knowledge that hearing decreases with aging, and as binaural beats depend on the hearing of the patient, the efficiency of the technique might be questionable in elderly patients. Young children can also be uncooperative when binaural beats are used. The main limitation of this study is the absence of a placebo. As the binaural beats are supposed to show their effects only in stereo mode, the same sound presented in mono mode could be used as a “sham” treatment, that is, a placebo.
Conclusion Binaural beats may be valuable to reduce preoperative anxiety, and we recommend further studies with different frequencies and application times. Adding a sham treatment group will increase the reliability of the results.
Conflict of interest We have no conflicts of interest.
Ethics statement/confirmation of patients’ permission This study was approved by the local ethics committee (approval number 41980859/050.01). Patients’ permission was obtained.
References 1. Appukuttan DP. Strategies to manage patients with dental anxiety and dental phobia: literature review. Clin Cosmet Investig Dent 2016;8:35–50. 2. Tellez M, Potter CM, Kinner DG, et al. Computerized tool to manage dental anxiety: a randomized clinical trial. J Dent Res 2015;94(9 suppl):174s–80s. 3. Karnad MP. Dental anxiety—how would you manage it? SAAD Dig 2015;31:26–31. 4. Brahm CO, Lundgren J, Carlsson SG, et al. Dentists’ views on fearful patients. Problems and promises. Swed Dent J 2012;36:79–89. 5. Torres-Lagares D, Recio-Lora C, Castillo-Dali G, et al. Influence of state anxiety and trate anxiety in postoperative oral surgery. Med Oral Patol Oral Cir Bucal 2014;19:e403–8. 6. Oster G. Auditory beats in the brain. Sci Am 1973;229:94–102.
Please cite this article in press as: Isik BK, et al. Effectiveness of binaural beats in reducing preoperative dental anxiety. Br J Oral Maxillofac Surg (2017), http://dx.doi.org/10.1016/j.bjoms.2017.02.014
YBJOM-5129; No. of Pages 4
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ARTICLE IN PRESS B.K. Isik et al. / British Journal of Oral and Maxillofacial Surgery xxx (2017) xxx–xxx
7. Gao X, Cao H, Ming D, et al. Analysis of EEG activity in response to binaural beats with different frequencies. Int J Psychophysiol 2014;94:399–406. 8. Appukuttan D, Vinayagavel M, Tadepalli A. Utility and validity of a single-item visual analog scale for measuring dental anxiety in clinical practice. J Oral Sci 2014;56:151–6. 9. Facco E, Stellini E, Bacci C, et al. Validation of visual analogue scale for anxiety (VAS-A) in preanesthesia evaluation. Minerva Anestesiol 2013;79:1389–95. 10. Luyk NH, Beck FM, Weaver JM. A visual analogue scale in the assessment of dental anxiety. Anesth Prog 1988;35:121–3. 11. Cohen SM, Fiske J, Newton JT. The impact of dental anxiety on daily living. Br Dent J 2000;189:385–90. 12. Wahbeh H, Calabrese C, Zwickey H, et al. Binaural beat technology in humans: a pilot study to assess neuropsychologic, physiologic, and electroencephalographic effects. J Altern Complement Med 2007;13:199–206. 13. Pratt H, Starr A, Michalewski HJ, et al. A comparison of auditory evoked potentials to acoustic beats and to binaural beats. Hear Res 2010;262:34–44.
14. Zampi DD. Efficacy of theta binaural beats for the treatment of chronic pain. Altern Ther Health Med 2016;22:32–8. 15. Abeln V, Kleinert J, Struder HK, et al. Brainwave entrainment for better sleep and post-sleep state of young elite soccer players − a pilot study. Eur J Sport Sci 2014;14:393–402. 16. Lane JD, Kasian SJ, Owens JE, et al. Binaural auditory beats affect vigilance performance and mood. Physiol Behav 1998;63:249–52. 17. Padmanabhan R, Hildreth AJ, Laws D. A prospective, randomised, controlled study examining binaural beat audio and pre-operative anxiety in patients undergoing general anaesthesia for day case surgery. Anaesthesia 2005;60:874–7. 18. Goodin P, Ciorciari J, Baker K, et al. A high-density EEG investigation into steady state binaural beat stimulation. PLoS One 2012;7:e34789. 19. Vernon D, Peryer G, Louch J, et al. Tracking EEG changes in response to alpha and beta binaural beats. Int J Psychophysiol 2014;93:134–9.
Please cite this article in press as: Isik BK, et al. Effectiveness of binaural beats in reducing preoperative dental anxiety. Br J Oral Maxillofac Surg (2017), http://dx.doi.org/10.1016/j.bjoms.2017.02.014
ARTICLE IN PRESS Available online at www.sciencedirect.com
ScienceDirect British Journal of Oral and Maxillofacial Surgery xxx (2017) xxx–xxx
Effectiveness of binaural beats in reducing preoperative dental anxiety B.K. Isik a,∗ , A. Esen a , B. Büyükerkmen b , A. Kilinc¸ a , D. Menziletoglu a a b
Necmettin Erbakan University, Faculty of Dentistry, Oral and Maxillofacial Surgery Department, Konya, Turkey Necmettin Erbakan University, Faculty of Dentistry, Prosthodontics Department, Konya, Turkey
Accepted 26 February 2017
Abstract Binaural beats are an auditory illusion perceived when two different pure-tone sine waves are presented one to each ear at a steady intensity and frequency. We evaluated their effectiveness in reducing preoperative anxiety in dentistry. Sixty patients (30 in each group) who were to have impacted third molars removed were studied (experimental group: 20 women and 10 men, mean (range) age 24 (18-35) years, and control group: 22 women and 8 men, mean (range) age 28 (15-47) years). All patients were fully informed about the operation preoperatively, and their anxiety recorded on a visual analogue scale (VAS). The local anaesthetic was given and the patients waited for 10 minutes, during which those in the experimental group were asked to listen to binaural beats through stereo earphones (200 Hz for the left ear and 209.3 Hz for the right ear). No special treatment was given to the control group. In both groups anxiety was then recorded again, and the tooth removed in the usual way. The paired t test and t test were used to assess the significance of differences between groups. The degree of anxiety in the control group was unchanged after the second measurement (p = 0.625), while that in the experimental group showed a significant reduction in anxiety (p = 0.001). We conclude that binaural beats may be useful in reducing preoperative anxiety in dentistry. © 2017 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Keywords: Binaural beats; anxiety; dental anxiety; preoperative anxiety; dental fear; oral surgery
Introduction Anxiety is an emotional state that precedes a threatening encounter, which sometimes is not even identifiable,1 and is common both for dental patients and professionals. It can prevent patients making regular visits to the dentist, and it has the potential to affect their quality of life.2,3 It can evoke physical, cognitive, emotional, and behavioural responses, and managing such patients is stressful for many dentists.4 Because anxiety is often closely linked to painful stimuli and increased perception of pain, affected patients experience
∗ Corresponding author at: Necmettin Erbakan Üniversitesi, Dis Hekimligi Fakültesi, Konya, Turkey. Tel.: +90 332 220 00 25, Fax: +90 332 220 00 45. E-mail address: [email protected] (B.K. Isik).
more pain that lasts longer, and they need more analgesics.1,5 Psychotherapeutic or pharmacological interventions, or both, have been suggested to deal with it.1 Binaural beats occur when two sounds with steady intensities but different frequencies are presented separately, one to each ear. The resulting perception is of a single tone with a frequency that is midway between the two carrier tones and that waxes and wanes in amplitudes at a rate equal to the difference between them. They require the combined action of both ears.6 Their use is not new and much research has been done,7 but we know of no report of their use in dental anxiety. In this prospective randomised clinical study we investigated the efficacy of binaural beats on anxiety among patients about to have impacted third molars removed.
http://dx.doi.org/10.1016/j.bjoms.2017.02.014 0266-4356/© 2017 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Please cite this article in press as: Isik BK, et al. Effectiveness of binaural beats in reducing preoperative dental anxiety. Br J Oral Maxillofac Surg (2017), http://dx.doi.org/10.1016/j.bjoms.2017.02.014
YBJOM-5129; No. of Pages 4
2
ARTICLE IN PRESS B.K. Isik et al. / British Journal of Oral and Maxillofacial Surgery xxx (2017) xxx–xxx
Patients and method The study was approved by the local ethics committee (approval number 41980859/050.01). Inclusion criteria were having a fully impacted mandibular third molar tooth that required removal, and being otherwise healthy. Patients who had psychiatric or hearing disorders or epilepsy, or who were taking antidepressants, anticonvulsants, or opioids, were excluded. We included 60 volunteers who were randomly divided into experimental and control groups (n = 30 in each). There were 20 women and 10 men in the experimental group, whose mean (range) age was 24 (18-35) years, and 22 women and 8 men in the control group, whose mean (range) age was 28 (15-47) years. Randomisation was by the toss of a coin. Before the operations all patients were told that they had an impacted tooth that needed to be removed. The operation was outlined (without getting graphic), and it was explained that postoperatively they could expect some pain, swelling, and temporary inability to open the mouth completely. They then recorded their degree of anxiety on a visual analogue scale (VAS), which has previously been shown to be a valid way in which to evaluate dental anxiety.8–10 This scale comprised a 100 mm horizontal line drawn on paper, the left-hand end of which was marked “no anxiety at all”, and the right-hand end “worst anxiety imaginable”. There were no other expressions or numbers on the line. Patients were asked to make a mark that indicated their degree of anxiety on the line, which was measured (mm) from the left-hand end. This record was labelled “first measurement”. In the control group, the local anaesthetic was given, and they waited for 10 minutes. During this period, nothing was done, there was no background music or noise, and we did not talk to the patient about the operation. The operating room and table was prepared in the usual way. After the 10 minute’ period was over, patients’ anxiety was recorded again. This was labelled “second measurement”. In the experimental group the local anaesthetic was given and the patient was asked to listen to binaural beats through stereo earphones (200 Hz for the left ear and 209.3 Hz for the right ear). The frequencies were produced by software (Brain Waves Binaural Beats, MynioTech Apps, Chapeco, Santa Catarina, Brazil) running on a mobile device (Samsung Galaxy S II, Samsung Electronics Co Ltd, South Korea). The patients were allowed to adjust the volume as they wished. The binaural beats that we used were “pure” frequencies: that is, there was no background music or another soothing sound such as rain drops or waves. After the patient had listened to 10 minutes of binaural beats, the earphones were taken off and the anxiety recorded again. This was labelled “second measurement” in the experimental group. All patients were instructed not to close their eyes during the waiting period, as this could affect the natural brainwaves and interfere with our results. The operations were then con-
Table 1 Mean (SD) first and second visual analogue scores for anxiety in experimental and control groups (n = 30 in each). Measurement
Experimental
Control
First Second p value
5.37 (2.12) 3.59 (2.23) <0.01
5.52 (2.42) 5.39 (2.65) 0.625
tinued in the usual way. The type of incision, volume, and type of local anaesthetic were the same in both groups. Statistical analysis We used SigmaPlot 12.5 (Systat Software Inc, San Jose, CA, USA) for statistical analyses. The data were tested for normality with the Shapiro-Wilk test. The data satisfied the requirements for parametric tests, so the significance of differences between the groups was assessed with the aid of the paired t test and intergroup comparisons were assessed with the t test. Probabilities of 0.05 or less were accepted as significant.
Results At the first measurement there was no significant difference (p = 0.402) between the anxiety felt in the experimental and control groups (t = −0,250, df 58; 95% CI of the difference between means −1.323 to 1.030; difference = −0.147). At the second measurement the difference between the two groups was significant (p = 0.006), the experimental group having less anxiety (Table 1) (t = −2.843, df 58; 95% CI −3.061 to −0.532; difference = −1.797). As we could find no similar report elsewhere we considered our research as a pilot study and made a post hoc power analysis, which showed a power of 0.88 at an ␣ of 0.05. On within-group analyses there was a significant decrease (p < 0.001) in anxiety in the experimental group (t = 7.258, df 29; 95% CI for difference of means 1.278 to 2.282; difference between means = 1.780). However, in the control group there was no significant difference (p = 0.625) between the first and second measurements (t = 0.494, df 29; 95% CI for difference of means −0.408 to 0.668; difference between means = 0.130).
Discussion Treating an anxious patient is stressful. Cooperation is poor, treatment takes longer, and it is likely to be an unpleasant experience for both patient and dentist.4 The physiological effects may include feelings of exhaustion after a visit to the dentist, while the cognitive impact can involve unhelpful thoughts, beliefs, and fears, together with avoidance and other behaviour related to eating and oral hygiene. Disturbances of sleep and social interactions,
Please cite this article in press as: Isik BK, et al. Effectiveness of binaural beats in reducing preoperative dental anxiety. Br J Oral Maxillofac Surg (2017), http://dx.doi.org/10.1016/j.bjoms.2017.02.014
YBJOM-5129; No. of Pages 4
ARTICLE IN PRESS B.K. Isik et al. / British Journal of Oral and Maxillofacial Surgery xxx (2017) xxx–xxx
and feelings of low self-esteem and self-confidence, have also been reported.11 Dental anxiety can also discourage the patient from future visits.1 There is no single, universally effective management for dental anxiety. Drugs have been used to achieve sedation, as has general anaesthesia. In a sedated state, pulmonary and cardiovascular functions are not affected but cognitive function and physical coordination are reduced. The use of general anaesthesia is obviously reserved for more challenging cases such as severe anxiety, phobia, and psychiatric disorders.1 Psychotherapeutic interventions have also been tried. Indeed, cognitive behaviour therapy has been highly successful.1 Binaural beats were first reported in the nineteenth century and described in detail by Oster in 1973.6 The theory behind them is to present a sound with a steady intensity and frequency to one ear and another sound with the same intensity but slightly different frequency to the other ear. As a result the brain produces pulsations in the amplitude and localisation that is the same with the perceived sounds. These pulsations are known as “binaural beats” or “binaural tones”.7 It has been suggested that tones with a frequency from 200 to 900 Hz are more effective in provoking binaural beats than those that exceed 1000 Hz.12,13 The difference in frequency between the two sounds must be less than 30 Hz for the beats to occur, otherwise the two tones are captured independently, and no beats are perceived.7 Many studies have reported the psychological and physiological effects of binaural beats. For example, treatment of chronic pain,14 improving the quality of sleep,15 improving vigilance,16 and decreasing preoperative anxiety.17 There is, however, no agreement about the mechanism of binaural beats. The basic hypothesis is that the human brain alters its dominant EEG frequency towards the frequency of external stimuli to synchronise neural activity with stimuli from binaural beats.7 However, some authors disagree with this explanation, and have reported no significant differences in cortical frequency during the period of stimulation with binaural beats compared with a white noise signal.18,19 VAS is known to be valid for evaluating dental anxiety,8–10 and a VAS of 4.8 or more indicates dental anxiety.8 In our study, mean anxiety scores were 5.37 for the experimental group and 5.52 for the control group on the first measurement. We may therefore surmise that both groups had dental anxiety when they entered the operating theatre. At the second measurement, we found the anxiety scores 3.59 for the experimental group and 5.39 for the control group, which suggests that the use of binaural beats reduced anxiety, while merely waiting in the operating theatre was ineffective. Because we could find no previous studies about the use of binaural beats in dental publications, we had no guidelines for calculating the frequency and duration of the binaural beats. We chose the frequency (9.3 Hz) from the ␣ band to produce a relaxing effect. A duration of 10 minutes was set empirically, as it was considered to be long enough to see the effect of the local anaesthetic solution and short enough
3
to be used in a routine clinical environment. It is possible to change these variables and test the outcomes. Dentists can easily use binaural beats to decrease preoperative anxiety. There are numerous computer programs that can produce them for all major operating systems and many of them are free. A personal computer, a tablet, or a smartphone (already available in most dental surgeries) can therefore be used. There are even pre-recorded binaural beats that can be downloaded from the internet and listened to with a music player. Age can limit the effect of binaural beats. It is common knowledge that hearing decreases with aging, and as binaural beats depend on the hearing of the patient, the efficiency of the technique might be questionable in elderly patients. Young children can also be uncooperative when binaural beats are used. The main limitation of this study is the absence of a placebo. As the binaural beats are supposed to show their effects only in stereo mode, the same sound presented in mono mode could be used as a “sham” treatment, that is, a placebo.
Conclusion Binaural beats may be valuable to reduce preoperative anxiety, and we recommend further studies with different frequencies and application times. Adding a sham treatment group will increase the reliability of the results.
Conflict of interest We have no conflicts of interest.
Ethics statement/confirmation of patients’ permission This study was approved by the local ethics committee (approval number 41980859/050.01). Patients’ permission was obtained.
References 1. Appukuttan DP. Strategies to manage patients with dental anxiety and dental phobia: literature review. Clin Cosmet Investig Dent 2016;8:35–50. 2. Tellez M, Potter CM, Kinner DG, et al. Computerized tool to manage dental anxiety: a randomized clinical trial. J Dent Res 2015;94(9 suppl):174s–80s. 3. Karnad MP. Dental anxiety—how would you manage it? SAAD Dig 2015;31:26–31. 4. Brahm CO, Lundgren J, Carlsson SG, et al. Dentists’ views on fearful patients. Problems and promises. Swed Dent J 2012;36:79–89. 5. Torres-Lagares D, Recio-Lora C, Castillo-Dali G, et al. Influence of state anxiety and trate anxiety in postoperative oral surgery. Med Oral Patol Oral Cir Bucal 2014;19:e403–8. 6. Oster G. Auditory beats in the brain. Sci Am 1973;229:94–102.
Please cite this article in press as: Isik BK, et al. Effectiveness of binaural beats in reducing preoperative dental anxiety. Br J Oral Maxillofac Surg (2017), http://dx.doi.org/10.1016/j.bjoms.2017.02.014
YBJOM-5129; No. of Pages 4
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ARTICLE IN PRESS B.K. Isik et al. / British Journal of Oral and Maxillofacial Surgery xxx (2017) xxx–xxx
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Please cite this article in press as: Isik BK, et al. Effectiveness of binaural beats in reducing preoperative dental anxiety. Br J Oral Maxillofac Surg (2017), http://dx.doi.org/10.1016/j.bjoms.2017.02.014