Melatonin premedication versus placebo in wisdom teeth extraction: a randomised controlled trial

Anxiolytic and Sedative Properties of Melatonin Premedication in Pediatrics Undergoing Elective Cardiac Catheterization: A Randomized Placebo Study

BACKGROUND

Preoperative anxiety in children has been linked to various postoperative consequences, such as postoperative regressive behavioral issues, extended distress during the recovery period, eating disorders, and bedwetting. The current study aimed to investigate the efficacy of low-dose oral melatonin in alleviating preoperative anxiety among children in the Iraqi population.

STUDY DESIGN

A randomized, double-blinded comparative study was undertaken, involving children aged four to 14 years scheduled for elective cardiac catheterization under general anesthesia. The study comprised a total of 80 children. The involved individuals were randomly assigned to two groups, each with 40 subjects. Group A received 0.5 mg/kg melatonin as premedication, while Group B received a placebo.

RESULTS

The two groups demonstrated similarity in mean age, weight, cardiac disease, and gender distribution. Statistically significant reductions in anxiety scores were observed in the melatonin group compared to the placebo group. Particularly, children administered 0.5 mg/kg melatonin exhibited the most substantial anxiolysis and venipuncture compliance (P < 0.05). Additionally, children who were premedicated with melatonin experienced decreased cognition, maximum sedation, successful parental separation, and psychomotor impairment (P < 0.05).

CONCLUSIONS

Melatonin demonstrated an effective sedation level without significant side effects, making it a preferred choice due to its efficacy, safety, current availability, and cost-effectiveness compared to other anesthetic agents used in premedication procedures.

Association between single-nucleotide polymorphisms in serotonin receptor 2A and melatonin receptor 1A genes and pain after root canal treatment

AIM

This study aimed to investigate whether single-nucleotide polymorphisms (SNPs) in the genes encoding 5-HTR2A (5-Hydroxytryptamine (serotonin) receptor 2A) and MTNR1A (melatonin receptor 1A) may contribute to postoperative pain perception after root canal treatment. We hypothesised that SNPs in HTR2A and MTNR1A genes were associated with postoperative pain after root canal treatment.

METHODOLOGY

This genetic cohort study enrolled patients with single-rooted teeth diagnosed with pulp necrosis and asymptomatic apical periodontitis before root canal treatment. Root canal treatment was performed in one session using a standardized protocol. Postoperative pain and tenderness were assessed using a visual analogue scale (recorded every day for 7 days and on the 14th and 30th days after root canal treatment). Genomic DNA was extracted from saliva and used to genotype the SNPs in HTR2A (rs4941573 and rs6313) and MTNR1A (rs6553010, rs6847693 and rs13140012) using real-time polymerase chain reaction. Genotypes were compared using univariate and multivariate Poisson regression with generalized estimating equations (p < .05).

RESULTS

In total, 108 patients were enrolled in this study. The SNPs rs6553010 (MTNR1A), rs4941573 and rs6313 (HTR2A) were associated with an increased risk of developing pain after root canal treatment (p < .05).

CONCLUSIONS

This study suggests that SNPs in HTR2A and MTNR1A influence pain response after root canal treatment.

Effects of melatonin on postoperative sleep quality: a systematic review, meta-analysis, and trial sequential analysis

PURPOSE

Postoperative sleep disturbances are common. Although several studies have examined the effect of melatonin on postoperative sleep disturbances, the results have not reached any definitive conclusion. We sought to conduct a systematic review to compare the effects of melatonin and melatonin agonists on postoperative sleep quality with those of placebo or no treatment in adult patients who underwent surgery under general or regional anesthesia.

METHODS

We searched MEDLINE, Cochrane Central Register of Controlled Trials, Embase, Web of Science, ClinicalTrials.gov, and the UMIN Clinical Trials Registry up to 18 April 2022. Randomized clinical trials examining the effects of melatonin or melatonin agonists in patients undergoing general or regional anesthesia with sedation for any surgery were eligible for inclusion. The primary outcome was sleep quality measured using a visual analog scale (VAS). The secondary outcomes were postoperative sleep duration, sleepiness, pain, opioid consumption, quality of recovery, and adverse events. A random-effects model was used to combine the results. We assessed study quality with the Cochrane Risk of Bias Tool version 2. We applied a trial sequential analysis to assess the precision of the combined results.

RESULTS

Eight studies (516 participants) were analyzed for sleep quality. Of those, four studies used only a short duration of melatonin, either on the night before and the day of surgery or only on the day of surgery. A random-effects meta-analysis showed that melatonin did not improve sleep quality measured by VAS compared with placebo (mean difference, -0.75 mm; 95% confidence interval, -4.86 to 3.35), with low heterogeneity (I2, 5%). Trial sequential analysis revealed that the accrued information size (n = 516) reached the estimated required information size (n = 295). We downgraded the certainty of the evidence because of the high risk of bias. The effect on postoperative adverse events was comparable between the melatonin and control groups.

CONCLUSION

Our results indicate that melatonin supplementation does not improve postoperative sleep quality measured with the VAS compared with placebo in adult patients (GRADE: moderate).

STUDY REGISTRATION

PROSPERO (CRD42020180167); registered 27 October 2022.

The Effect of Melatonin on Analgesia, Anxiety, and Intraocular Pressure (IOP) in Cataract Surgery Under Topical Anesthesia

PURPOSE

This study investigated the effect of oral melatonin as a premedication before cataract surgery on pain score, anxiety, surgical conditions, and intraocular pressure (IOP) during cataract surgery with phacoemulsification under topical anesthesia.

DESIGN

This randomized, double-blind prospective study was conducted among 120 patients aged 50 to 80.

METHODS

Patients were randomly assigned to receive either sublingual melatonin 3 mg or placebo 60 min before surgery. Verbal anxiety and pain scores, heart rate, systolic and diastolic blood pressure, intraocular pressure, and quality of surgical conditions were recorded. The results were analyzed using SPSS 23 software, and statistical analysis consisted of χ² test and t-test, and a P value less than .05 was considered significant.

FINDINGS

There was a significant difference between the two groups regarding pain after the surgery before being discharged from the recovery room. The mean pain score in the melatonin group was lower than the placebo group in T4 (in the postoperative ward) (P < .05). The anxiety score of patients was lower in the melatonin group in T3 and T4 (during surgery and in the postoperative ward, respectively) (P < .05). IOP was significantly lower in the case group at the end of the surgery after receiving premedication (P = .021).

CONCLUSIONS

This study showed that 3 mg Sublingual melatonin premedication for patients undergoing cataract surgery under topical anesthesia reduced patients' anxiety scores, pain score, and IOP.

The Effect of Local Melatonin Application Following the Removal of an Impacted Mandibular Third Molar

PURPOSE

Pain, swelling, limitation of the mouth opening, development of intra-bony defects, and bone loss are common side effects of removing the impacted third molar. The purpose of this study was to measure the association of applying melatonin in the socket of an impacted mandibular third molar with osteogenic activity and the anti-inflammatory effects.

METHODS

This prospective, randomized, blinded trial comprised of patients who required removal of the impacted mandibular third molar. The patients were divided into two groups (n = 19) as follows: melatonin group (3 mg of melatonin into 2 ml of 2% hydroxyethyl cellulose gel was packed into the socket) and placebo group (2 ml of 2% hydroxyethyl cellulose gel was placed in the socket). The primary outcome was bone density, measured using Hounsfield unit immediately after surgery and 6 months later. Secondary outcome variables included serum osteoprotegerin level (Ng/ml) that measured immediately, 4 weeks and 6 months postoperatively. Other clinical outcome measures were pain by visual analog scale, maximum mouth opening (MMO) (millimeter), and swelling (millimeter) that were evaluated immediately, 1, 3, and 7 days postoperatively. The data were analyzed by independent t-test of Wilcoxon's rank-sum, analysis of variance, and generalized estimating equation (P ≤ .05).

RESULTS

Thirty-eight patients (25 female and 13 males) with a median age of 27 years were enrolled in the study. There was no statistical significance in bone density observed in both groups [melatonin group: 978.5(951.3-1015.8), control group: 965.8 (924.6-998.7), P = .1]. Alternatively, there were statistically significant improvements in osteoprotegerin levels (on week 4), MMO (on day1), and swelling (on day 3) in the melatonin group compared to those in the placebo group [1.9(1.4-2.4), 39.68 ± 1.35, and 14.36 ± 0.80 versus 1.5(1.2-1.4); 38.33 ± 1.20, and 14.88 ± 0.59; P = .02, .003, 0.031, respectively]. The pain values showed statistically significant improvement throughout the follow-up period in the melatonin group compared to the placebo group [5(3-8), 2(1-5), and 0(0-2) versus 7(6-8), 5(4-6), and 2(1-3); P < .001, respectively].

CONCLUSIONS

The results support the anti-inflammatory effect of melatonin in reducing the pain scale and swelling. Furthermore, it plays a role in the improvement of MMO. On the other hand, the osteogenic activity of melatonin could not be detected.

Evaluation of the Effects of Exogenous Melatonin in Zygomatic Complex Fractures

Objective

The objective of this research was to evaluate the benefits of using exogenous melatonin in the preoperative period of patients with zygomatic complex fractures.

Materials and methods

A randomized, triple-blind clinical trial of independent samples was carried out. The sample was divided into two groups: G1 (melatonin) and G2 (placebo). Interventions were standardized with 10 mg melatonin or placebo the night before surgery and 1 h before the start of surgery. The studied variables were level of salivary cortisol, level of anxiety, pain, and use of rescue analgesics. Descriptive and inferential statistical analysis was performed, with a margin of error considered as 5%.

Results

A total of 14 patients were included, and after using the medication, the measurement of cortisol was reduced in the melatonin group (0.48 ± 0.25 to 0.43 ± 0.13 μg/100 ml) and increased in the placebo group (0.19 ± 0.12 to 0.23 ± 0.18 μg/100 ml). There was a reduction in the level of anxiety in the melatonin group and an increase in the placebo group. After two hours of surgery, the pain was statistically less in the melatonin group (4.50 ± 1.38) compared to the placebo group (6.17 ± 0.98). Six hours after surgery, pain showed regression in both groups. Patients in the placebo group (83.3%) used more rescue analgesics than melatonin group (33.3%) in the postoperative period.

Conclusions

Thus, this research demonstrated that melatonin can be effective in reducing salivary cortisol and anxiety after medication, and patients in the melatonin group needed less rescue analgesics in the postoperative period.

Melatonin in sleep disorders

Melatonin is the main hormone involved in the control of the sleep-wake cycle. It is easily synthesisable and can be administered orally, which has led to interest in its use as a treatment for insomnia. Moreover, as production of the hormone decreases with age, in inverse correlation with the frequency of poor sleep quality, it has been suggested that melatonin deficit is at least partly responsible for sleep disorders. Treating this age-related deficit would therefore appear to be a natural way of restoring sleep quality, which is lost as patients age. However, despite the undeniable theoretical appeal of this approach to insomnia, little scientific evidence is available that supports any benefit of this substitutive therapy. Furthermore, the most suitable dose ranges and pharmaceutical preparations for melatonin administration are yet to be clearly defined. This review addresses the physiology of melatonin, the different pharmaceutical preparations, and data on its clinical usefulness.

Effects of Melatonin Treatment on Perioperative Sleep Quality: A Systematic Review and Meta-Analysis with Trial Sequential Analysis of Randomized Controlled Trials

PURPOSE

Perioperative sleep disorders have attracted much attention due to their high prevalence and severe harm, and the current treatment methods are insufficient. Some randomized controlled trials (RCTs) have produced controversial results on whether melatonin can improve perioperative sleep quality. This review aimed to evaluate the effects of melatonin treatment on perioperative sleep quality.

PATIENTS AND METHODS

A systematic search of six databases was performed to identify RCTs investigating melatonin and perioperative sleep. The outcomes analyzed were subjective sleep quality, sleep latency (SL), total sleep time (TST), sleep efficiency (SE), the behavior of awakenings and daily naps, and the incidence of poor sleep quality. RevMan 5.4 and Stata 16 software was used for the meta-analysis and sensitivity analysis, and trial sequential analysis was conducted using TSA 0.9.5.10 Beta software. This study was registered in PROSPERO (registration number: CRD42022311378).

RESULTS

10 studies containing 725 participants were included. Melatonin improved postoperative subjective sleep quality (SMD: -0.30; 95% CI: [-0.47, -0.14]; P = 0.0004) but not preoperative sleep quality (MD: -2.76; 95% CI: [-10.44, 4.91]; P = 0.48). In the postoperative period, 6mg dose had the best efficacy (SMD: -0.31; 95% CI: [-0.57, -0.04]; P = 0.02). Melatonin increased postoperative TST (P = 0.02) and SE (P = 0.002) and decreased the incidence of postoperative poor sleep quality (P = 0.002) but had no effect on SL (P = 0.11), the number and duration of awakenings (P = 0.28; P=0.55), and the number and duration of daily naps (P = 0.26; P = 0.38). The trial sequential analysis showed that the accumulated Z value crossed both the traditional boundary value and the TSA boundary value, further confirming the stability of the result of the meta-analysis.

CONCLUSION

Melatonin treatment can improve postoperative sleep quality. A 6mg daily dose of melatonin may have a better beneficial effect, which needs further exploration. This study supports the application of melatonin for improving postoperative sleep quality.

Melatonin as an adjunctive treatment on dental procedures: A systematic review

The systematic review tried to answer the following question: Does the melatonin administered systemically or topically ameliorate patients involved with oral health conditions or dental procedures? The systematic review has been registered in the PROSPERO (2021CRD42021095959). Eligibility criteria included only randomized controlled clinical trials (RCTs) with at least 10 participants that compared patients that received melatonin as a treatment before and/or after their oral intervention topically or systemically, with control patients. A search was performed in PubMed/MEDLINE, Web of Science, Cochrane Library, and Academic Google databases for articles up to February 2021. The Cochrane risk-of-bias tool for randomized clinical trials was used and revealed that the studies included presented low risk of bias for the majority of criteria assessed. It was selected 25 articles, of which only six did not demonstrate positive effects and three presented null effects with the use of melatonin. Melatonin has improved the inflammatory response in periodontal disease, dental surgeries, and mucositis of head and neck oncologic irradiated patients. In addition, it showed anxiolytic potential in patients that were submitted to dental procedures. In conclusion, melatonin favored the treatment of oral changes when used topically and systemically.

Melatonin for preoperative and postoperative anxiety in adults

BACKGROUND

Anxiety in relation to surgery is a well-known problem. Melatonin offers an alternative treatment to benzodiazepines for ameliorating this condition in the preoperative and postoperative periods.

OBJECTIVES

To assess the effects of melatonin on preoperative and postoperative anxiety compared to placebo or benzodiazepines.

SEARCH METHODS

We searched the following databases on 10 July 2020: CENTRAL, MEDLINE, Embase, CINAHL, and Web of Science. For ongoing trials and protocols, we searched clinicaltrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform.

SELECTION CRITERIA

We included randomized, placebo-controlled or standard treatment-controlled (or both) studies that evaluated the effects of preoperatively administered melatonin on preoperative or postoperative anxiety. We included adult patients of both sexes (15 to 90 years of age) undergoing any kind of surgical procedure for which it was necessary to use general, regional, or topical anaesthesia.

DATA COLLECTION AND ANALYSIS

One review author conducted data extraction in duplicate. Data extracted included information about study design, country of origin, number of participants and demographic details, type of surgery, type of anaesthesia, intervention and dosing regimens, preoperative anxiety outcome measures, and postoperative anxiety outcome measures.

MAIN RESULTS

We included 27 randomized controlled trials (RCTs), involving 2319 participants, that assessed melatonin for treating preoperative anxiety, postoperative anxiety, or both. Twenty-four studies compared melatonin with placebo. Eleven studies compared melatonin to a benzodiazepine (seven studies with midazolam, three studies with alprazolam, and one study with oxazepam). Other comparators in a small number of studies were gabapentin, clonidine, and pregabalin. No studies were judged to be at low risk of bias for all domains. Most studies were judged to be at unclear risk of bias overall. Eight studies were judged to be at high risk of bias in one or more domain, and thus, to be at high risk of bias overall. Melatonin versus placebo Melatonin probably results in a reduction in preoperative anxiety measured by a visual analogue scale (VAS, 0 to 100 mm) compared to placebo (mean difference (MD) -11.69, 95% confidence interval (CI) -13.80 to -9.59; 18 studies, 1264 participants; moderate-certainty evidence), based on a meta-analysis of 18 studies. Melatonin may reduce immediate postoperative anxiety measured on a 0 to 100 mm VAS compared to placebo (MD -5.04, 95% CI -9.52 to -0.55; 7 studies, 524 participants; low-certainty evidence), and may reduce delayed postoperative anxiety measured six hours after surgery using the State-Trait Anxiety Inventory (STAI) (MD -5.31, 95% CI -8.78 to -1.84; 2 studies; 73 participants; low-certainty evidence). Melatonin versus benzodiazepines (midazolam and alprazolam) Melatonin probably results in little or no difference in preoperative anxiety measured on a 0 to 100 mm VAS (MD 0.78, 95% CI -2.02 to 3.58; 7 studies, 409 participants; moderate-certainty evidence) and there may be little or no difference in immediate postoperative anxiety (MD -2.12, 95% CI -4.61 to 0.36; 3 studies, 176 participants; low-certainty evidence). Adverse events Fourteen studies did not report on adverse events. Six studies specifically reported that no side effects were observed, and the remaining seven studies reported cases of nausea, sleepiness, dizziness, and headache; however, no serious adverse events were reported. Eleven studies measured psychomotor and cognitive function, or both, and in general, these studies found that benzodiazepines impaired psychomotor and cognitive function more than placebo and melatonin. Fourteen studies evaluated sedation and generally found that benzodiazepine caused the highest degree of sedation, but melatonin also showed sedative properties compared to placebo. Several studies did not report on adverse events; therefore, it is not possible to conclude with certainty, from the data on adverse effects collected in this review, that melatonin is better tolerated than benzodiazepines.

AUTHORS' CONCLUSIONS

When compared with placebo, melatonin given as premedication (as tablets or sublingually) probably reduces preoperative anxiety in adults (measured 50 to 120 minutes after administration), which is potentially clinically relevant. The effect of melatonin on postoperative anxiety compared to placebo (measured in the recovery room and six hours after surgery) was also evident but was much smaller, and the clinical relevance of this finding is uncertain. There was little or no difference in anxiety when melatonin was compared with benzodiazepines. Thus, melatonin may have a similar effect to benzodiazepines in reducing preoperative and postoperative anxiety in adults.

Effect of Melatonin on Postoperative Pain and Perioperative Opioid Use: A Meta-analysis and Trial Sequential Analysis

OBJECTIVES

We performed this meta-analysis in order to assess the effect of melatonin on postoperative pain and perioperative opioid consumption.

METHODS

We systematically searched PubMed, EMBASE, and the Cochrane Library until October 2019 for studies concerning the effect of melatonin vs. placebo on postoperative pain. We also searched for grey literature in ClnicalTrials.gov and grey literature databases, including OpenGrey and Grey Literature Report. We performed a meta-analysis of postoperative pain scores, perioperative opioid use, the number of patients with analgesic requirements, the time to the first analgesic requirement, length of hospital stay, and common reported adverse events of melatonin.

RESULTS

According to the inclusion and exclusion criteria, 15 studies with a total of 1,102 patients were included in the final analysis. Melatonin was significantly associated with decreased VAS score (24 hours postoperatively) compared to placebo (trial sequential analysis = conclusive; mean difference [MD] -0.86; 95% confidence interval [CI] -1.38, -0.34; P = 0.001). Patients randomly assigned to melatonin were administered less postoperative opioids than patients in the control groups (trial sequential analysis = inconclusive; MD -3.33 mg; 95% CI -5.28, -1.38; P = 0.0008). The need for analgesic requirements was significantly decreased in the melatonin group. Patients who received melatonin had a significantly longer time to the first analgesic requirement. Compared to the placebo group, there were no significant differences in terms of length of hospital stay, dizziness, headache, paresthesia, and nausea.

CONCLUSIONS

Given the low quality of evidence, minor degree of VAS score reduction, and inconclusive trial sequential analysis of postoperative opioid consumption, this meta-analysis neither supports nor opposes the effect of melatonin on postoperative pain.

Analgesic Efficacy of Melatonin: A Meta-Analysis of Randomized, Double-Blind, Placebo-Controlled Trials

Previous systematic reviews and meta-analyses of randomized controlled trials have reported controversial findings regarding the effects of melatonin on pain reduction. The aim of this study was to evaluate the efficacy of melatonin on pain among adults using a meta-analysis of randomized, double-blind, placebo-controlled trials (RDBPCTs). PubMed, EMBASE, the Cochrane Library, and the bibliographies of relevant articles were searched up to February 2020. Two of the authors independently evaluated eligibility of the studies based on the pre-determined criteria and extracted data. Standardized mean differences (SMDs) with 95% confidence intervals (CIs) for the pain score change were calculated using a random-effects meta-analysis. Out of 463 that met the initial criteria, a total of 30 trials, which involved 1967 participants with 983 in an intervention group and 984 in a control group, were included in the final analysis. In a random-effects meta-analysis, the use of melatonin reduced chronic pain in all the trials (5 studies, SMD -0.65, 95% CI -0.96 to -0.34, I² = 57.2%) and high-quality trials (4 studies, SMD -0.62, 95% CI -1.01 to -0.23, I² = 49.3%). Moreover, the use of melatonin significantly reduced acute postoperative pain (11 studies, SMD -0.82, 95% CI -1.40 to -0.25, I² = 93.0%). However, the subgroup meta-analysis of high-quality RDBPCTs showed no significant association between them (6 studies, SMD -0.21, 95 % CI -0.66 to 0.24, I² = 82.4%). The current study suggests that melatonin might be used in treatment of chronic pain, while there is no sufficient evidence for acute postoperative or procedural pain. Further trials are warranted to confirm its analgesic effect.

Fear and anxiety managing methods during dental treatments: a systematic review of recent data

INTRODUCTION

The management of anxiety and fear of patients experiencing medical treatment is always a major issue. Dentistry is a branch of medicine that is daily in managing these problems, especially in the case of pediatric patients. Odontophobia can be managed in different ways, and the purpose of this study is to eventually review which methods are currently accepted and which are the most effective.

EVIDENCE ACQUISITION

The literature analysis was conducted on a number of articles, suitably skimmed, after a first research, obtained from the most common scientific databases. The number of works included in the review is 28.

EVIDENCE SYNTHESIS

From the RCTs evaluated we could highlight that there are different methods in the literature, equally effective and certainly conditioned by the systemic condition of the patient. Another chapter instead turns out to be that linked to the management of the syndromic patient.

CONCLUSIONS

It is clear that there are different methods and equally different ways to manage our patients in the event of non-cooperation in the case of dental care. In addition to proper management by the clinician, in the literature methods linked to audiovisual distractions, hypnosis or pharmacological methods that produce conscious sedation are effectively reported.

The Effect of Melatonin on Anxiety and Pain of Tourniquet in Intravenous Regional Anesthesia

Background:

Melatonin has anxiolytic and potential analgesic effects. Several studies have indicated the sedative and anti-anxiety effects of melatonin when used as premedication before surgery. Hence, we assessed the efficacy of melatonin premedication in tourniquet-related pain and analgesia in patients receiving intravenous regional anesthesia (IVRA).

Materials and Methods:

Fifty patients undergoing elective hand surgery under IVRA were randomly divided into two groups (25 patients each) to receive either melatonin 6 mg (melatonin group) or placebo (control group) as oral premedication. IVRA was achieved with lidocaine, 3 mg/kg, diluted with saline to a total volume of 40 mL. Anxiety scores, sensory and motor block onset and recovery times, tourniquet pain, and 24-h analgesic requirements were recorded.

Results:

The onset of motor and sensory block was statistically significantly shorter in Group M (P < 0.001), and recovery of motor and sensory block was statistically significantly longer in Group M (P < 0.001). The time of starting tourniquet pain was longer in Group M (P < 0.001). The mean anxiety score in the study group was 3 ± 0.81 and in the control group was 4.20 ± 1.04 (P = 0.001). There was a statistically significant difference in the need for opioids between the two groups (P < 0.05).

Conclusions:

Melatonin is an effective premedication before IVRA because it reduces patient anxiety, decreases tourniquet-related pain, and improves perioperative analgesia.

Should Melatonin Be Used as an Alternative Sedative and Anxiolytic Agent in Mandibular Third Molar Surgery?

PURPOSE

Melatonin is a natural hormone that regulates circadian rhythms. The aim of this study was to compare the anxiolytic effects of oral melatonin and oral midazolam in patients undergoing third molar surgery. The study also sought to investigate the effects of these drugs on cognitive and psychomotor functions.

MATERIALS AND METHODS

This was a double-blinded, prospective, randomized clinical study. Patients scheduled for impacted third molar surgery were included in the study. Anxiety was evaluated with the visual analog scale (VAS). To measure psychomotor and cognitive functions before the procedure, all patients were asked to complete the digit symbol substitution test (DSST) and the trail making test (TMT parts A and B). Then, all patients were allocated to 1 of 3 groups to receive oral midazolam 0.2 mg/kg (group MD), oral melatonin 0.4 mg/kg (group M), or an oral multivitamin tablet as placebo (group P). After 60 minutes, patients were reassessed using the same 3 tests. The difference between the pre- and post-drug VAS values was calculated and the anxiolytic effects of the drugs were evaluated.

RESULTS

Ninety patients participated in the study. No relevant differences were observed among groups for age, gender, or duration of operation. The results suggested that anxiety decreased most in group MD (P < .001), but anxiety in group M also decreased significantly compared with group P (P = .016). Similarly, the greatest increase in TMT-A and -B score differences was in group MD compared with the other groups (P < .001), whereas there was no significant difference between groups M and P for TMT-A and -B scores (P = .913 and P = .964, respectively).

CONCLUSION

Melatonin showed sufficient anxiolytic effect in third molar surgery without affecting cognitive and psychomotor functions.

Oral Melatonin Versus Midazolam as Premedication for Intravenous Sedation in Pediatric Dental Patients

OBJECTIVES

This study aimed to evaluate the effect of oral melatonin and oral midazolam as premedication for intravenous (IV) sedation of pediatric dental patients.

MATERIALS AND METHODS

This crossover, double-blind randomized clinical trial was conducted on 23 uncooperative 2-6-year-olds with definitely negative behaviors according to the Frankl's scale. Each child served as their own control. The children were randomly divided into two groups: group I received 0.5mg/kg of oral melatonin one hour before IV sedation, while group II received 0.5mg/kg of oral midazolam 30 minutes before IV sedation on their first visit. Every child received the other premedication on their second visit. The degree of sedation was judged according to the Houpt scale. Physiologic parameters including blood pressure (PB), heart rate (HR), and blood oxygen saturation (SpO2) and side effects including dizziness, nausea, vomiting, and sleepiness were assessed. The parents' and the operator's satisfaction rates were scored. Data were analyzed using paired t-test and Wilcoxon signed-rank test.

RESULTS

There were significant differences in sedation scores between the two sessions (P<0.05). However, there were no significant differences in alterations of physiologic parameters between the two sessions (P>0.05). Nausea and vomiting were more common during the first two hours in the midazolam group (P=0.002). Tremors were more common in the melatonin group (P=0.013). Dizziness was more evident when melatonin was used (P<0.001). The clinician and the parents were more satisfied with the results of midazolam intake (P<0.05).

CONCLUSIONS

Premedication with oral midazolam in pediatric patients is superior to that with melatonin with a higher parents' and operator's satisfaction.

Melatonin and Comorbidities in Children with Autism Spectrum Disorder

PURPOSE OF REVIEW

Melatonin is used to treat sleep difficulties associated with autism spectrum disorder (ASD). There are growing evidence that melatonin could have an effect on other symptoms than sleep, such as anxiety, depression, pain, and gastrointestinal dysfunctions. Interestingly, these symptoms frequently are found as comorbid conditions in individuals with ASD. We aimed to highlight the potential effect of melatonin on these symptoms.

RECENT FINDINGS

Animal and human studies show that melatonin reduces anxiety. Regarding the effect of melatonin on pain, animal studies are promising, but results remain heterogeneous in humans. Both animal and human studies have found that melatonin can have a positive effect on gastrointestinal dysfunction.

SUMMARY

Melatonin has the potential to act on a wide variety of symptoms associated with ASD. However, other than sleep difficulties, no studies exist on melatonin as a treatment for ASD comorbid conditions. Such investigations should be on the research agenda because melatonin could improve a multitude of ASD comorbidities and, consequently, improve well-being.

Exogenous melatonin in the treatment of pain: a systematic review and meta-analysis

Melatonin is an important hormone for regulating mammalian circadian biology and cellular homeostasis. Recent evidence has shown that melatonin exerts anti-nociception effects in both animals and humans. However, according to clinical trials, the anti-nociception effects of melatonin are still controversial. The aim of this meta-analysis was to investigate the anti-nociception effects of melatonin premedication. The primary outcome was the effects of melatonin on pain intensity. The secondary outcomes included the number of patients with analgesic requirements, total analgesic consumption, and brain-derived neurotrophic factor (BDNF) levels. In total, 19 studies were included in the current meta-analysis. The pooling data show that melatonin significantly decreased the pain intensity, as evidenced by the pain scores. Moreover, melatonin administration also reduced the proportion of patients with analgesic requirements and BDNF levels. However, the effects of melatonin on total analgesic consumption still require further confirmation. Collectively, the current meta-analysis supports the use of melatonin for anti-nociception.

The role of stress hormones in dental management behavior problems

Dental management behavior problems are thought to be both multifactorial and multidimensional, consisting of physiological, behavioral and cognitive components. The stress response to pain or even the anticipation of distress initiates activation of the hypothalamic-pituitary-adrenal axis and causes an increase of cortisol and catecholamines. The literature on the role of hormones in dental management behavior problems comprises about one hundred papers, which have mainly been focused on this activation of the HPA axis in various situations in dental care. They have generally used salivary cortisol as a marker of the activity of the HPA axis, sometimes combined with salivary alpha amylase. Here we summarize the literature data on the role of stress hormones in dental management behavior problems.