Three experimental groups of 20 patients each, all of whom were to undergo fixed orthodontic treatment, were enrolled in this prospective study. Group 1 was given a placebo, group 2 was given 400 mg ibuprofen, and group 3 was given 550 mg naproxen sodium. All the patients received only one dose that was given one hour before archwire placement. All patients were asked to complete a questionnaire concerning the pain perceived after archwire placement. The questionnaire was in the form of a seven-page booklet that contained 100-mm horizontal Visual Analogue Scale on which the patient marked the degree of discomfort at the indicated time periods. The patients were instructed to make a check on the scale at each time interval to represent the perceived severity of pain during each of four activities, ie, chewing, biting, fitting back teeth together, and fitting front teeth together. Incidence and severity of pain were recorded by the patient at two hours, six hours, nighttime on the day of appointment, 24 hours after the appointment, and two days, three days, and seven days after bonding. The results revealed that patients taking 550 mg naproxen sodium one hour before archwire placement had significantly lower levels of pain at two hours, six hours, and nighttime after adjustment than patients taking placebo or ibuprofen. However, the use of additional postoperative doses was recommended to control orthodontic pain completely.
Pressure delivered to a tooth by orthodontic appliances results in ischemia, inflammation, and edema immediately after the compression of the periodontal ligament.1 Algogens such as histamine, bradykinin, prostaglandins, serotonin, and substance P are released after periodontal ligament compression and activation of the inflammatory reaction.2 Pain during orthodontic treatment usually appears at two hours after application of orthodontic force, reaches a peak level at 24 hours, and lasts approximately five days.3–6
Pain is of multifactorial nature and depends on variables such as patient's subjective previous pain experiences, age, type of appliance, present emotional state and stress, cultural differences, and sex.7 Studies evaluating the nature of pain felt after oral surgery procedures have reported possible sex differences in the degree of pain response.2,8 However, the situation is different for the orthodontic patient in that clinicians have not agreed on sex differences in the degree of pain felt by the orthodontic patient.9–11 Possible sex differences in orthodontic pain response are thought to be related to culture rather than to physiological factors.7
Discomfort and pain after initial seperator or archwire placement are common experiences among orthodontic patients. It is one of the main reasons that discourages patients from seeking orthodontic treatment.12 Pain during orthodontic treatment may have a negative influence on cooperation, and some patients may even stop brushing their teeth due to pain. In a study that consisted of 203 Chinese orthodontic patients, 91% of them reported pain caused by fixed orthodontic appliances and 39% reported pain during every visit.13 Kvam et al14 in Norway and Scheurer et al15 in Switzerland reported that 95% of orthodontic patients experienced varying degrees of discomfort during treatment.
Different methods have been developed to control pain during orthodontic treatment including the application of low-level laser therapy to periodontal tissues,16 transcutaneous electrical nerve stimulation (TENS),17,18 and vibratory stimulation of the periodontal ligament.19 To some degree these have been tried, and pain control has been achieved. However, the use of nonsteroidal anti-inflammatory drugs (NSAIDs) is the preferred method of pain control related to fixed orthodontic appliances. Anti-inflammatory drugs such as aspirin and ibuprofen have been evaluated in the previously literature.3,5,6,20 Ngan et al3 made the first studies on analgesics and evaluated the analgesic efficacy of ibuprofen and aspirin on 77 patients in a placebo-controlled, double-blind, single-dose study. They found that the placebo group felt more pain than the patients who had received either ibuprofen or aspirin. They also reported that patients who received ibuprofen after seperator or archwire insertion felt less pain than patients who received aspirin.
Recently much attention has been paid to preoperative analgesic consumption in both the medical and dental literature. Preoperative analgesic consumption provides the blockage of afferent nerve impulses before they reach the central nervous system. If NSAIDs are given before the procedure, the body absorbs them before tissue damage and subsequent prostaglandin production. It was reported previously that NSAID application before oral surgery decreases the pain intensity and delays both the onset and peak pain levels.20,21 In orthodontic literature, Law et al5 and Bernhart et al6 have evaluated the efficacy of preoperative analgesic consumption and both have found that ibuprofen taken one hour before archwire or band application decreases the pain levels from two hours after bonding until nighttime.
Only the efficacy of aspirin and ibuprofen has been studied so far in orthodontic literature. Naproxen sodium is a propionic acid derivate like ibuprofen, and its analgesic effect is comparable to ibuprofen.2 However, the duration of action of naproxen is longer than ibuprofen.2 The recommended schedule of administration is 500 mg initially, followed by 250 mg doses at 8- to 12-hour intervals.2 The aim of this study is to evaluate the efficacy of preoperative administration of ibuprofen and naproxen sodium on orthodontic pain after archwire placement.
MATERIALS AND METHODS
Sixty orthodontic patients who were scheduled to receive fixed orthodontic treatment agreed to participate in this study. The following selection criteria were required for participation: no prophylactic antibiotic coverage required; no systemic diseases; currently not using antibiotics or analgesics; no contraindication to the use of NSAID; a minimum weight requirement based on Food and Drug Administration–approved over-the-counter pediatric dosage labeling guidelines; no teeth extracted at least two weeks before bonding.
A detailed medical history was taken for each patient, and any patient with a history of a systemic disease was excluded from the study. Both the parents and the patients were informed about the procedure, and an informed consent was obtained.
Twenty patients were randomly assigned to each of three experimental groups, ie, group A, lactose capsule; group B, 400 mg ibuprofen; and group C, 550 mg naproxen sodium. In all groups, patients took only one tablet, one hour before archwire placement. The patient and research assistant were blinded to each subject's experimental group.
Subjects were given routine posttreatment instructions and were asked to complete a questionnaire at appropriate intervals during the week after the bonding appointment. The questionnaire was in the format of a seven-page booklet that contained 100-mm horizontal Visual Analogue Scale (VAS) on which the patient marked the degree of discomfort at the indicated time periods. The patients were instructed to make a check on the scale at each time interval to represent the perceived severity of pain/discomfort during each of four activities that included chewing, biting, fitting back teeth, and fitting front teeth. The incidence and severity of pain were recorded by the patient at two hours, six hours, bedtime on the day of appointment, 24 hours after the appointment, and two days, three days, and seven days after bonding. Patients were asked to return the questionnaire at the next appointment.
Patients were instructed not to take any additional analgesics. If additional “rescue” medication was needed, they were instructed to indicate the date and the dosage of the medication taken. All the patients returned their questionnaires, and none of them had taken any additional analgesics.
All the statistical analyses were made using the Statistical Package for Social Sciences 10.0 (SPSS Inc, Chicago, Ill). Descriptive statistics were calculated for pain scores at each time interval for the experimental groups. Analysis of variance (ANOVA) was used to find the differences in age among the groups.
Comparisons between the three experimental groups in four parameters were made using repeated measures two-way ANOVA. If the results of repeated measures ANOVA were found significant, one-way ANOVA was carried out for each time interval, and multiple comparisons were made with Tukey HSD test. In this study, level of significance for repeated measures ANOVA and Tukey test was determined as P < .05.
The descriptive statistics for the three experimental groups are given in Table 1. As a result of ANOVA, the mean ages of the subjects were similar between the three experimental groups (P < .05). Depending on the previous studies that revealed no differences in pain response between girls and boys, the findings were evaluated without sex discrimination.
According to the results of repeated measures ANOVA, there were significant relationships between drug groups and time in chewing, biting, fitting front teeth together, and fitting back teeth together (P < .05). The mean pain values and standard deviations for chewing, biting, fitting front teeth together, and fitting back teeth together in each of the three experimental groups are shown in Table 2.
Differences in postoperative pain between experimental conditions
The one-way ANOVA to compare the differences between the experimental groups at each time intervals showed significant differences in “pain to chewing” at two hours, at six hours, and at the night after bonding (P < .05). The results of Tukey test revealed significant differences between the placebo group and naproxen sodium group at two hours, six hours, and at night (P < .05). There was no significant difference in pain levels between groups at any subsequent postoperative times (Figure 1).
For “pain to biting,” significant differences were observed only at two hours and six hours (P < .05). At these two time intervals, patients who took naproxen sodium one hour before archwire placement felt less pain than patients taking both placebo and ibuprofen (P < .05) (Figure 2).
There were significant differences at two hours, six hours, and at nighttime in “pain when fitting front teeth together” (Figure 3) and “pain when fitting back teeth together” (Figure 4) (P < .05). The naproxen sodium group felt less pain than both placebo and ibuprofen groups in all these measurements. No significant differences were measured between the placebo and ibuprofen groups at these time intervals (P > .05).
This study was performed on 60 patients who were to undergo fixed orthodontic treatment. Three experimental groups included group 1, placebo; group 2, 400 mg ibuprofen; and group 3, 550 mg naproxen sodium. All the patients received only one dose that was given one hour before archwire placement.
The patients were asked to complete a questionnaire concerning the pain perceived after archwire placement. The questionnaire was in the form of a seven-page booklet that contained 100-mm horizontal VAS on which the patient marked the degree of pain/ discomfort at the indicated time periods. The patients were instructed to make a check on the scale at each time interval to represent the perceived severity of pain during each of four functional activities of chewing, biting, fitting back teeth together, and fitting front teeth together. The incidence and severity of pain were recorded by the patient at two hours, six hours, nighttime on the day of appointment, 24 hours after the appointment, and two days, three days and seven days after bonding.
Sex discrimination was not included because of previous results that had shown no correlation between pain and sex.9–11 Patients with similar ages, malocclusions, and social class were selected for this study.3
Because no method exists to measure a pain response objectively, we used a 100-mm VAS, which was shown to be a reliable and easy subjective method of measuring pain intensity.7
The results of this study reveal that patients who took naproxen sodium preoperatively had significantly less pain than patients who took placebo or ibuprofen while chewing, fitting front teeth, and fitting back teeth at two hours, six hours, and nighttime after archwire placement. The results of pain to biting were found to be quite similar, except that there were no differences in pain scores between the three experimental groups at nighttime. Jackson et al20 and Dionne and Cooper21 had previously found that NSAIDs taken before oral surgery procedures could delay the onset and severity of pain. The probable mechanism for preoperative anti-inflammatory effect is the blockage of prostaglandin synthesis in peripheral tissue. If NSAIDs were given before the procedure, the body absorbs them before prostaglandin production, and this decreases the inflammatory response. According to the results of the present study, when compared with the placebo group, the preoperative use of both ibuprofen and naproxen sodium decreased the pain levels at two hours and six hours after archwire placement, but the results were statistically significant for the naproxen sodium group only.
The studies that investigated the effects of preoperative analgesic administration before archwire placement so far have investigated only the effects of ibuprofen.5,6 Law et al5 found that preemptive ibuprofen significantly decreased pain to chewing at two hours compared with postoperative ibuprofen or placebo. Similar to that, Bernhart et al6 found decreased pain scores in patients taking pre- or postoperative ibuprofen compared with patients taking only postoperative ibuprofen.
The results of this study found no significant differences in pain responses between the placebo and ibuprofen groups. However, patients who took naproxen sodium one hour before archwire placement had decreased levels of pain. The disagreement with the findings of these two studies and the present study for the analgesic effect of ibuprofen is probably because of the multifactorial nature of pain. Individual pain response depends on variables such as the patient's subjective previous pain experiences, age, type of appliance, present emotional state and stress, cultural differences.7
Peak pain had occurred at night or 24 hours after archwire adjustment, and pain levels of the patients who agreed to participate in this study started to decrease at 24 hours after archwire placement. Naproxen sodium is a long-acting NSAID with analgesic activity requiring only twice a day dosage, and its effect has been studied in oral surgery.2 Single doses of 220 mg of naproxen and 200 mg of ibuprofen were comparable in onset of analgesic action and in pain relief but with prolonged duration of action of naproxen. In this study, naproxen sodium was found effective to reduce pain in pain to chewing, “pain to fitting front teeth,” and “pain to fitting back teeth” at two hour, six hours, and at nighttime after archwire placement. The analgesic activity of naproxen sodium was not sufficient in pain to biting even at the night after the adjustment. Therefore, it is recommended that in addition to one preoperative dose, at least one more postoperative analgesic tablet, preferably two, should be given to the orthodontic patient for pain control.
Gastric or duodenal ulceration, bleeding disorders, renal insufficiency, asthma, and allergy, hypertension, congestive heart problems, atherosclerosis, and interaction with antihypertension drugs are among the common adverse effects seen with NSAIDs.2 Kehoe et al22 found that ibuprofen significantly inhibited the production of prostaglandin E (PGE) in the periodontal ligament and, subsequently, decreased the rate of tooth movement.
On the other hand, although the acetaminophen had an inhibitory effect on peripheral prostaglandin (PGE) synthesis at the level of the periodontal ligament, the rate of tooth movement was not significantly different from the controls. They concluded that acetaminophen is the analgesic of choice for the relief of orthodontic discomfort. Walker and Buring23 reported that NSAIDs inhibit the cyclooxygenase pathway and therefore the production of PGE, and it was thought that NSAIDs may inhibit the osteoclastic activity necessary for tooth movement and slow the rate of orthodontic tooth movement. The dosage of the anti-inflammatory drugs used in these studies was much higher than over-the-counter therapeutic doses. In clinical orthodontics, lower doses are used for a short duration (1–3 days) after orthodontic activation. In a healthy patient without any systemic diseases, these doses are eliminated from the body before orthodontic tooth movement is started.
There is no standard care for analgesic usage to relieve pain caused by fixed orthodontic appliances. This study aimed to evaluate the analgesic effect of ibuprofen and naproxen sodium, and naproxen sodium was found to have superior analgesic activity compared with both ibuprofen and placebo. However, before reaching a final conclusion, several other studies evaluating the efficacy of safer and longer-acting NSAIDs are needed.
The results demonstrated that
Naproxen sodium (550 mg) taken one hour before archwire placement significantly decreased the severity of pain at two hours, six hours, and, except for pain to biting, 24 hours when compared with preoperatively administrated ibuprofen (400 mg) or placebo.
As maximum pain levels were felt on the night to 24 hours after archwire adjustment, a single dose of an analgesic given preoperatively was found insufficient to relieve pain; therefore, at least one additional postoperative dose is recommended.
Corresponding author: Omur Polat, DDS, PhD, Baskent Universitesi Diş Hekimliği Fakültesi, Ortodonti A.D. 11. sk. no: 26 06490 Bahçelievler, Ankara, Turkey (firstname.lastname@example.org)