Anxiety is an undesirable psychological phenomenon. Patients are usually anxious when subjected to third molar surgery, but the pattern of anxiety is unknown. The aim of this study was to assess the intensity and course of anxiety during third molar surgery. This study included 48 consecutive patients (mean age 25 ± 6 years) who had a third molar removed surgically under local anaesthesia. The heart rate was monitored continuously during treatment as a measure of anxiety. Preoperative anxiety was scored with the Modified Dental Anxiety Scale. Each patient’s anxiety level was assessed when in the waiting room, sitting down in the dental chair, during the application of local anaesthesia, application of surgical drapes, time-out procedure, incision, alveolotomy, removal of the third molar, and suturing, and at the end of the procedure. The lowest heart rates were recorded in the waiting room, in the dental chair, during anaesthesia, when applying surgical drapes, during suturing, and at the end of the procedure. The highest values were obtained during the time-out procedure, incision, and alveolotomy ( P < 0.005). In conclusion, the intensity and course of anxiety has a specific pattern during third molar surgery, with the lowest levels of anxiety prior to surgery and directly postoperative and the highest during the time-out procedure and the actual surgery.
Moderately to highly anxious patients experience more intense and prolonged postoperative pain and higher psychological co-morbidity when subjected to surgery. Amongst the many variables that affect the threshold for pain, anticipation and anxiety have been reported to be the most important.
Numerous procedures have been shown to provoke anxiety, such as sigmoidoscopy, colposcopy, percutaneous coronary interventions, and cardiac surgery. Anxiety most often peaks prior to the procedure and decreases immediately after the procedure. Whether this pattern also applies to oral surgery, e.g., removal of a third molar, is not yet known, although it has been reported that oral surgery is linked to specific and intensive fear. Furthermore, about 50% of patients are anxious about dental treatment. A visit to the dental clinic provokes feelings of anxiety, and increases blood pressure and heart rate.
Anxiety assessments have indicated a higher level of treatment anxiety for oral and maxillofacial surgery than for dental treatment. Therefore, the results of dental studies cannot be translated directly to oral and maxillofacial practice. The course of anxiety throughout the process of third molar removal has not been evaluated thoroughly. Therefore, the aim of this study was to assess the intensity and course of anxiety during oral and maxillofacial surgery treatments. This was done by measuring real-time heart rate changes before, during, and after the surgical removal of a third molar, as well as measuring the accompanying fear with the Modified Dental Anxiety Scale (MDAS). Detailed knowledge of the level and course of anxiety accompanying surgical third molar removal may help in identifying anxiety-reducing interventions.
Materials and methods
All consecutive patients seen during a 6-week period who were scheduled for the removal of a third molar under local anaesthesia and who were eligible when assessed against the study inclusion and exclusion criteria, were asked to join the study. Inclusion criteria encompassed patients with an indication for the removal of a lower third molar under local anaesthesia, aged between 18 and 40 years, and who were fluent in the Dutch language (to be able to complete the questionnaire). Exclusion criteria were a third molar removal or other oral or maxillofacial procedure within the past 6 months, medical conditions and the use of medications that may induce alterations in heart rate, and patients with an implanted pacemaker or implantable cardioverter defibrillator (ICD).
Ten minutes before surgery, the preoperative dental anxiety level (situation-specific trait anxiety) was estimated using the validated Dutch version of the MDAS. The MDAS consists of five questions, each with a five-category rating scale ranging from ‘not anxious’ to ‘extremely anxious’. Patients rated their emotional reaction during the anticipation of an appointment at the dental clinic, when in the waiting room, and in anticipation of drilling, scaling, and local anaesthetic injection. Responses were scored from 1 to 5, providing total scores ranging from 5 (not anxious at all) to 25 (extremely anxious). Dental anxiety scores of 19 or higher were considered as indicative of high dental trait anxiety.
After completing the questionnaire, the patient’s heart rate was recorded continuously until the end of the procedure using a Mio Alpha watch (Mio Alpha; Mio Global Physical Enterprises Inc., Vancouver, British Columbia, Canada), a watch with an accuracy comparable to the accuracy of an electrocardiogram (ECG). The real-time heart rate data were transmitted to a Bluetooth Smart Android operated pad. The electronics of the Alpha Mio watch are integrated into the back plate of the wristband and include an accelerometer enabling electro-optical cells to detect the pulsing volume of blood flow (photoplethysmography).
The study was approved by the hospital medical ethics commission. Informed consent was obtained from all patients prior to the study.
All consecutive patients who were eligible after application of the inclusion/exclusion criteria were asked to participate when they were scheduled for surgery. After obtaining informed consent, each patient had to complete the MDAS questionnaire, and demographic data were recorded (age, sex, medical history, use of medication, etc.). Next, the patient’s heart rate was measured using the continuous heart rate monitor. A Bluetooth link was established with an android tablet using the Bluetooth Low Energy heart rate monitor application (BLE Heart Rate Monitor; Pribble Software LLC, Germantown, Maryland, USA). This monitored and recorded the heart rate every second. The application recorded how much time had elapsed since the start of the heart rate measurements. The time elapsed was also scored on a form and was kept during the various stages of the surgical procedure. These stages were the moment the patient took a seat in the waiting room, when sitting down in the dental chair, the moment of application of local anaesthesia, application of the surgical drapes over the patient’s face, time-out procedure, moment of incision, alveolotomy, removal of the third molar, suturing, and the end of the procedure ( Table 1 ). After the patient had been connected to the heart rate monitor, the patient returned to his/her seat in the waiting room where they had to wait for at least 5 min. Subsequently, the patient was accompanied to the operating room and settled in the dental chair. The patient received routine verbal information and reassurance from the operating surgeon.
|Period||Measurement time point|
|1||In the waiting room|
|2||In the dental chair|
|3||During local anaesthesia|
|4||During the application of surgical drapes|
|5||During the time-out procedure|
|8||During removal of the third molar|
|10||At the end of the procedure|
|Additional anaesthetics||During the administration of additional anaesthesia|
The two senior oral and maxillofacial surgeons were familiar with the aim of this study. The surgical procedure was standardized. In short, the surgical field was anaesthetized by mucosal infiltration and blocking of the inferior alveolar nerve with two to three carpules of local anaesthetic (40 mg articaine hydrochloride per millilitre (4%), with 0.01 mg epinephrine; 1.7 ml per carpule). After local anaesthesia, the surgical field was isolated with sterile drapes, leaving the patient’s nose and mouth exposed. The time-out protocol followed, which consisted of the verification of the patient’s identity and the aim of the procedure. This time-out procedure is a ‘second time’ time-out procedure. In the study clinic, the patient’s data are checked as soon as the patient is called in from the waiting room. After checking the anaesthetic state of the mucosa, the surgeon made an incision and created a mucoperiosteal flap. After alveolectomy, when necessary, the third molar was removed and the flap was repositioned and sutured. After surgery, routine postoperative instructions, including the use of ibuprofen, were provided to the patient. Subsequently, the Mio Alpha watch was disconnected.
A power analysis with a power of 90% and a two-sided significance level of 0.005 was used (with 10 tests as the primary outcome, for the 10 time periods; see Table 1 ). The significance level of 0.005 was used because the Bonferroni correction was necessary, as 10 tests were used as the primary outcome. Calculations of the sample size were based on paired-samples t -tests, in which a non-parametric analysis was taken into account by adding 10% to the total sample size. Sample size calculations were performed using SamplePower 2.0 (SPSS Inc., Chicago, IL, USA).
A significant change in heart rate of 10 beats per minute (bpm), with a standard deviation of the paired difference of 10.7 (based on a standard deviation of 12 bpm and a correlation between the paired observations of r = 0.6), resulted in a minimum calculated sample size of 25. By adding 10% for the possibility of non-parametric testing, the sample size required was 27.5. Another 10% was added for the attrition rate. This resulted in a minimum sample size of 31 patients to be collected during the 6-week patient inclusion period.
The data were processed in two different ways. The first approach consisted of selecting 15 s of heart rate measurements before and 15 s after the moment of onset of an event. This approach was used in order to investigate the impact of an individual event on the heart rate of a participant. An interval of 30 s around a specific event was estimated to be representative. The second approach was limited to an interval of 15 s of heart rate measurements after the onset of an event. This time-period directly after the onset of an event was considered as representative of the heart rate during that event. This approach was chosen to compare the different events to each other and to determine whether any differences in heart rate occurred between the events during the whole treatment process.
Data were analyzed using IBM SPSS Statistics version 22.0 (IBM Corp., Armonk, NY, USA). The Shapiro–Wilk test, Kolmogorov–Smirnov test, and graphical interpretation of normal Q–Q plots were used to determine the distribution of the data. If the data did not appear to be normally distributed, transformation was applied in order to obtain a normal distribution. Where applicable, paired- or independent-samples t -tests, Wilcoxon signed-rank tests, Friedman tests with post hoc testing, and Mann–Whitney U -tests were applied. With the Bonferroni correction taken into account, each individual hypothesis was tested at α = 0.005.
Within the recruitment period of 6 weeks, 53 participants were eligible to join the study. All patients were willing to participate. Of these 53 patients, two had to be excluded from the final analysis due to an alternative treatment, one patient because of a vasovagal collapse during treatment, one anxious patient because she persisted in removing the sterile drapes from her face, and one patient because of an extremely high heart rate (209 bpm). In this latter case, surgery was temporarily stopped to assess the stability of the patient. The remaining 48 patients, ranging in age from 18 to 40 years (mean 25 ± 6 years), were included in the data analysis; 20 were men (mean age 25 ± 7 years) and 28 were women (mean age 24 ± 5 years). Thirty-six (75%) of the participating patients had a mandibular third molar removed and 12 (25%) had a combination of maxillary and mandibular third molar removals on one side. Of the 48 participants, eight had pain complaints during treatment and needed additional anaesthetics. An alveolotomy was needed to remove the third molar in 31 out of the 48 participants.
Changes in heart rate during the course of third molar removal
All data, except data from the period ‘pain’ and the period ‘additional anaesthetics’, were not normally distributed. As transformation of the data did not result in a normal distribution, the Wilcoxon signed-rank test was used for the analysis of these data. The periods ‘pain’ and ‘additional anaesthetics’ were evaluated using paired samples t -tests.
A significant and sudden increase in heart rate occurred when the patient sat down in the dental chair (period ‘during dental chair’) and when the surgical drapes were put on the patient (period ‘during surgical drapes’, Fig. 1 ).
The experience of pain was not accompanied by a significant increase in heart rate (mean before pain 117 bpm, mean during pain 116.5 bpm). However, after additional anaesthesia, the heart rate dropped significantly (mean before 104.6 bpm, mean during the application of extra anaesthesia 100.4 bpm; P = 0.003).
Heart rates compared between different events
The heart rate varied significantly during the course of the events: χ 2 (9) = 72.933, P < 0.0005 (Friedman’s test, pairwise comparisons, Bonferroni adjustment, significance set at P = 0.005; Fig. 2 ).
Sex-related differences in heart rate
Heart rate was significantly lower in men (median 91.4 bpm) than in women (median 94.9 bpm) ( P = 0.028, Mann–Whitney U -test). Although a basal difference in heart rate between male and female participants was found, they showed a similar pattern of heart rate variation during the treatment ( Fig. 3 ).
Modified Dental Anxiety Scale
The mean MDAS score was 9 ± 3.3, with a minimum score of 5 and a maximum of 18. All MDAS scores pointed towards low to moderate anxiety levels. None of the participants was extremely anxious. Males had a significantly lower mean MDAS score (8.1 ± 2.4) than females (10.3 ± 3.7).
Heart rate showed a specific pattern during the course of the events around third molar surgery under local anaesthesia. Specific events elicited an increase (sitting down in the dental chair, eyes being covered with surgical drapes) or decrease (administration of additional anaesthesia) in heart rate. This pattern is in accordance with the literature. Alemany-Martinez et al. reported the lowest heart rate values before the start of the surgical procedure and the highest values during incision and flap-raising. Houston et al. found a considerably increased heart rate (by 12 bpm) during the action of sitting down in the dental chair. Meyer and Goldstein et al. pointed out that the most marked changes in heart rate were observed just before the application of local anaesthetic and during the extraction.
In the present study, a trend towards a higher heart rate before administering anaesthetic (median 89.5 bpm) compared to the heart rate during the injection (median 88.5 bpm) was observed, but this finding did not reach statistical significance ( P = 0.516). Also, the application of additional anaesthetics in the case of pain during treatment elicited a significant decrease in heart rate. This appears to be in accordance with the literature, where the most pronounced increase in heart rate was found immediately before the injection of local anaesthetic, whereas the heart rate decreased during the actual injection.
Similar cardiovascular reactions were observed before and during the injection of isotonic saline and even during a pseudoinjection, whereby the syringe was placed in the mouth but the needle did not touch the mucosa. This suggests that patient (anticipation) anxiety mainly contributes to an increased heart rate. With this in mind, the decrease in heart rate during the injection may be due to the relatively pain-free way of giving local anaesthetics, and the reassuring effect on the patient.
Differences between men and women
The higher median heart rate in women than in men agrees with the generally slightly faster sinus rate in women. Also, the higher MDAS score in females than in males is in accordance with other studies assessing sex differences in anxiety-provoking stimuli.
Methods of assessing anxiety
Various physiological manifestations of anxiety can be observed to determine the presence of anxiety. For example, increased respiration, muscle tension, blood pressure, plasma epinephrine levels, electrical activity of the brain, and the palmar sweat index are physiological measures of fear. A number of methodological problems are encountered with these physiological indices, such as poor reliability and low practicality in the testing field. Pain and anxiety reactions during dental treatment stimulate the adrenal medulla to release endogenous epinephrine, which has a direct impact on the heart rate. The amount of stress experienced is usually measured by the level of anxiety reported by the patient. The use of physiological measures to gauge anxiety (heart rate) in test situations is considered to be more reliable than self-reported measures, because it is difficult to control voluntary autonomic nervous system responses. Also, heart rate measurements are relatively easy to obtain and therefore probably have a low effect on anxiety. Therefore, a physiological measurement (heart rate) was combined with a self-reported index to properly assess anxiety in this study.
One of the objectives of this study was to gather meaningful information on the course and intensity of anxiety during oral and maxillofacial surgery. This information will assist in the search for anxiety-reducing interventions to reduce patient stress and subsequent negative stress-related effects. Although all participants stated their anxiety level as mild to moderate, their anxiety fluctuated during the procedure. In line with these results, special attention should be paid to the most anxiety-provoking moments, i.e. the time-out procedure, the appliance of surgical drapes, the incision, the alveolotomy, and the actual removal of the third molar.
In conclusion, anxiety accompanying third molar surgery increases from the start of the treatment to the moment the third molar is actually removed and declines thereafter. Specific anxiety-provoking events are sitting down in the dental chair and the application of the surgical drapes over the patient’s face.
The study was approved by the medical ethics commission (METc) of Scheper Hospital (METc study number SH2014/1).
1. Scott L.E., Clum G.A., Peoples J.B.: Preoperative predictors of postoperative pain. Pain 1983; 15: pp. 283-293.
2. Muglali M., Komerik N.: Factors related to patients’ anxiety before and after oral surgery. J Oral Maxillofac Surg 2008; 66: pp. 870-877.
3. Arntz A., van Eck M., Heijmans M.: Predictions of dental pain: the fear of any expected evil, is worse than the evil itself. Behav Res Ther 1990; 28: pp. 29-41.
4. Liau F.L., Kok S.H., Lee J.J., Kuo R.C., Hwang C.R., Yang P.J., et. al.: Cardiovascular influence of dental anxiety during local anesthesia for tooth extraction. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008; 105: pp. 16-26.
5. Simon A.E., Steptoe A., Wardle J.: Socioeconomic status differences in coping with a stressful medical procedure. Psychosom Med 2005; 67: pp. 270-276.
6. Byrom J., Clarke T., Neale J., Dunn P.D., Hughes G.M., Redman C.W., et. al.: Can pre-colposcopy sessions reduce anxiety at the time of colposcopy? A prospective randomised study. J Obstet Gynaecol 2002; 22: pp. 415-420.
7. Trotter R., Gallagher R., Donoghue J.: Anxiety in patients undergoing percutaneous coronary interventions. Heart Lung 2011; 40: pp. 185-192.
8. Vingerhoets G.: Perioperative anxiety and depression in open-heart surgery. Psychosomatics 1998; 39: pp. 30-37.
9. Soh G., Yu P.: Phases of dental fear for four treatment procedures among military personnel. Mil Med 1992; 157: pp. 294-297.
10. Brand H.S., Gortzak R.A., Palmer-Bouva C.C., Abraham R.E., Abraham-Inpijn L.: Cardiovascular and neuroendocrine responses during acute stress induced by different types of dental treatment. Int Dent J 1995; 45: pp. 45-48.
11. Eli I., Schwartz-Arad D., Baht R., Ben-Tuvim H.: Effect of anxiety on the experience of pain in implant insertion. Clin Oral Implants Res 2003; 14: pp. 115-118.
12. Stouthard M.E., Hoogstraten J.: Prevalence of dental anxiety in the Netherlands. Commun Dent Oral Epidemiol 1990; 18: pp. 139-142.
13. Brand H.S., Abraham-Inpijn L.: Cardiovascular responses induced by dental treatment. Eur J Oral Sci 1996; 104: pp. 245-252.
14. DiAngelis N., Luepker R.V.: The effect of the dental setting on blood pressure measurement. Am J Public Health 1983; 73: pp. 1210-1212.
15. Hermes D., Matthes M., Saka B.: Treatment anxiety in oral and maxillofacial surgery. Results of a German multi-centre trial. J Craniomaxillofac Surg 2007; 35: pp. 316-321.
16. Meyer F.U.: Haemodynamic changes under emotional stress following a minor surgical procedure under local anaesthesia. Int J Oral Maxillofac Surg 1987; 16: pp. 688-694.
17. Goldstein D.S., Dionne R., Sweet J., Gracely R., Brewer H.B., Gregg R., et. al.: Circulatory, plasma catecholamine, cortisol, lipid, and psychological responses to a real-life stress (third molar extractions): effects of diazepam sedation and of inclusion of epinephrine with the local anesthetic. Psychosom Med 1982; 44: pp. 259-272.
18. Alemany-Martinez A., Valmaseda-Castellon E., Berini-Aytes L., Gay-Escoda C.: Hemodynamic changes during the surgical removal of lower third molars. J Oral Maxillofac Surg 2008; 66: pp. 453-461.
19. Humphris G.M., Freeman R., Campbell J., Tuutti H., D’Souza V.: Further evidence for the reliability and validity of the Modified Dental Anxiety Scale. Int Dent J 2000; 50: pp. 367-370.
20. Corah N.L.: Development of a dental anxiety scale. J Dent Res 1969; 48: pp. 596.
21. Humphris G.M., Morrison T., Lindsay S.J.: The Modified Dental Anxiety Scale: validation and United Kingdom norms. Commu Dent Health 1995; 12: pp. 143-150.
22. Humphris G.M., Dyer T.A., Robinson P.G.: The modified dental anxiety scale: UK general public population norms in 2008 with further psychometrics and effects of age. BMC Oral Health 2009; 9: pp. 20.
23. Newton J.T., Edwards J.C.: Psychometric properties of the modified dental anxiety scale: an independent replication. Commun Dent Health 2005; 22: pp. 40-42.
24. Valenti G., Westerterp K.R.: Optical heart rate monitoring module validation study.2013 IEEE International Conference on Consumer Electronics (ICCE).2013.IEEEpp. 195.
25. Gungormus M., Buyukkurt M.C.: The evaluation of the changes in blood pressure and pulse rate of hypertensive patients during tooth extraction. Acta Med Austriaca 2003; 30: pp. 127-129.
26. Freeman R., Clarke H.M., Humphris G.M.: Conversion tables for the Corah and Modified Dental Anxiety Scales. Commun Dent Health 2007; 24: pp. 49-54.
27. Houston J.B., Appleby R.C., DeCounter L., Callaghan N., Funk D.C.: Effect of r-epinephrine-impregnated retraction cord on the cardiovascular system. J Prosthet Dent 1970; 24: pp. 373-376.
28. Paramaesvaran M., Kingon A.M.: Alterations in blood pressure and pulse rate in exodontia patients. Aust Dent J 1994; 39: pp. 282-286.
29. Yokobayashi T., Nakajima T., Yagata H., Yatabe Y.: Changes of heart rate during administration of local anesthetics in the oral region. J Oral Surg 1977; 35: pp. 961-967.
30. McCarthy F.M.: A clinical study of blood pressure responses to epinephrine-containing local anesthetic solutions. J Dent Res 1957; 36: pp. 132-141.
31. Salman I., Schwartz S.P.: Effects of vasoconstrictors used in local anesthetics in patients with diseases of the heart. J Oral Surg (Chic) 1955; 13: pp. 209-213.
32. Kumar P., Clark M.: Kumar and Clark clinical medicine.7th edition2009.Elsevier SaundersEdinburghpp. 715-716.
33. Mellor A.C.: Dental anxiety and attendance in the north-west of England. J Dent 1992; 20: pp. 207-210.
34. Doebling S., Rowe M.M.: Negative perceptions of dental stimuli and their effects on dental fear. J Dent Hyg 2000; 74: pp. 110-116.
35. Holtzman J.M., Berg R.G., Mann J., Berkey D.B.: The relationship of age and gender to fear and anxiety in response to dental care. Spec Care Dentist 1997; 17: pp. 82-87.
36. Gadbury-Amyot C.C., Williams K.B.: Dental hygiene fear: gender and age differences. J Contemp Dent Pract 2000; 1: pp. 42-59.
37. Peretz B., Efrat J.: Dental anxiety among young adolescent patients in Israel. Int J Paediatr Dent 2000; 10: pp. 126-132.
38. ter Horst G., de Wit C.A.: Review of behavioural research in dentistry 1987–1992: dental anxiety, dentist–patient relationship, compliance and dental attendance. Int Dent J 1993; 43: pp. 265-278.
39. Guyton A.C., Hall J.E.: Textbook of medical physiology.11th edition2006.Elsevier SaundersPhiladelphia, PA p. 148, 206, 207, 254