Factors associated with pain induced by orthodontic separators

Impact of orthodontic treatment on OHRQoL of adolescents: a longitudinal study

OBJECTIVE

The aim of this study was to evaluate the extent to which orthodontic treatment need is perceived by the patients and by the orthodontist, as well as the possible impacts on the OHRQoL (Oral Health-Related Quality of Life) over the course of conventional orthodontic treatment in adolescent patients.

METHODS

The sample consisted of 55 adolescents. The perception of patients and orthodontists relative to the malocclusion was evaluated by the IOTN (Index of Orthodontic Treatment Need). The OHRQoL was evaluated by the Child-OIDP (Child-Oral Impacts on Daily Performances) questionnaire before the conventional orthodontic appliance was bonded (T0); and at the following time intervals: after one week (T1), one month (T2), three months (T3), six months (T4), and after the end of orthodontic treatment (T5).

RESULTS

Adolescents who had large orthodontic treatment needs had a poor OHRQoL, according to their self-perception (p=0.003) and according to the orthodontist's perception (p<0.001), when compared with patients with small and moderate needs. There was statistically significant difference in the OHRQoL between the time intervals T0 and T1 (p=0.021), T2 and T3 (p<0.001), T3 and T4 (p=0.033), and T0 and T5 (p<0.002). At the end of treatment, all evaluated participants reported an improvement in OHRQoL.

CONCLUSIONS

It was concluded that adolescents and orthodontists agreed with regard to the perception of orthodontic treatment need. In the first week and in the first month of orthodontic treatment, there was a negative impact on the OHRQoL. After three months, an improvement of OHRQoL was detected, which has progressed over time.

Biological and psychological factors affecting the sensory and jaw motor responses to orthodontic tooth movement

Orthodontic tooth movement (OTM) is associated with an inflammatory response, tooth pain (i.e. orthodontic pain) and changes in dental occlusion. Clinical realms and research evidence suggest that the sensory and jaw motor responses to OTM vary significantly among individuals. While some adjust well to orthodontic procedures, others may not and can experience significant pain or not adjust to occlusal changes. This is of concern, as clinicians cannot anticipate an individual's sensorimotor response to OTM. Converging evidence shows that some psychological states and traits significantly affect the sensorimotor response to OTM and may considerably affect an individual's adaptation to orthodontic or other dental procedures. We performed a topical review to synthesize the available knowledge about the behavioural mechanisms regulating the sensorimotor response to OTM, with the intent of informing orthodontic practitioners and researchers about specific psychological states and traits that should be considered while planning orthodontic treatment. We report on studies focusing on the role of anxiety, pain catastrophising, and somatosensory amplification (i.e. bodily hypervigilance), on sensory and jaw motor responses. Psychological states and traits can significantly affect sensory and jaw motor responses and a patient's adaptation to orthodontic procedures, although large interindividual variability exists. Clinicians can use validated instruments (checklists or questionnaires) to collect information about patients' psychological traits, which can assist in identifying those individuals who may not adjust well to orthodontic procedures. The information included in this manuscript also assists researchers investigating the effect of orthodontic procedures and or/appliances on orthodontic pain.

The effects of orthodontic treatment type, depression, and treatment need on perceived pain intensity

Objectives:

The objectives of this study were to evaluate how orthodontic treatment type, treatment need, and depression affect perceived pain intensity (PPI).

Material and Methods:

This prospective study included 172 patients (80 girls and 92 boys, mean age 14.32 ± 1.57 years) treated at the Sivas Cumhuriyet University Faculty of Dentistry, Department of Orthodontics. The patients were divided into three groups: the first group was treated with fixed orthodontic appliances, the second group was treated with twin blocks, and the third group was treated with rapid maxillary expansion and reverse headgear (RME/RH). Data were collected and classified with the Index of Orthodontic Treatment Need-Dental Health Component (DHC), Children’s Depression Scale, and Visual Analog Scale. PPI was recorded in the 1st week (T0), 2nd week (T1), the 1st month (T2), 2nd month (T3), 3rd month (T4), and the 6th month (T5).

Results:

PPI was higher in boys at T1 (P = 0.005) compared with girls. There was a significant difference of PPI between the treatment groups at T2 (P = 0.036), T3 (P = 0.012), T4 (P = 0.000), and T5 (P = 0.006). A statistically significant positive correlation was found between DHC and PPI at T3 (r = 0.182; P = 0.000), T4 (r = 0.161; P = 0.03), and T5 (r = 0.189; P = 0.000) time periods. There was no significant correlation between depression and PPI.

Conclusion:

Girls were more resistant to pain than boys. The type of treatment and the need for treatment both had an effect on PPI. Further studies are needed to investigate the effects of psychological states on PPI during orthodontic treatment.

Effects of Low-Level Laser Therapy on Dentin Hypersensitivity in Periodontally Compromised Patients Undergoing Orthodontic Treatment: A Randomised Controlled Trial

OBJECTIVES

This study aimed to assess the effects of low-level laser therapy (LLLT) on dentin hypersensitivity (DH) in periodontally compromised patients undergoing orthodontic treatment.

METHODS

This triple-blinded randomised controlled trial included 143 teeth with DH from 23 periodontally compromised patients. Teeth on one side of the dental arch were randomly assigned to the LLLT group (LG), while those on the contralateral side were allocated to the non-LLLT group (NG). After orthodontic treatment commenced, patients' orthodontic pain (OP) perceptions were documented in pain diaries. DH was assessed chairside by a visual analogue scale (VASDH) at fifteen timepoints across the orthodontic treatment and retention. VASDH scores were compared among timepoints by the Friedman test, among patients with varying OP perceptions using the Kruskal-Wallis tests, and between the LG and NG with the Mann-Whitney U test.

RESULTS

DH generally decreased over the observation (p < 0.001). The VASDH scores differed among patients with varying OP perceptions at multiple timepoints (p < 0.05). The generalized estimating equation model showed teeth in the LG had a significantly lower VASDH score than the NG at the 3rd month of treatment (p = 0.011).

CONCLUSION

LLLT could be potentially beneficial in managing DH in periodontally compromised patients undergoing orthodontic treatment.

Influence of anxiety and catastrophizing on pain perception in orthodontic treatment and its association with inflammatory cytokines

Pain is common in orthodontic treatment, is subject to individual variation, and is associated with anxiety and stress, which can potentially become catastrophizing. The aim of the present study was to determine the variability of pain response after the insertion of orthodontic separators and to assess the association of pain levels with dental anxiety, catastrophizing, tooth sensitivity, and genetic expression of cytokines. To this end, 70 patients of both genders were divided into two equal groups according to the elastomeric separator used: G1 (Dentaurum) and G2 (Orthometric). Two separators were inserted in the mesial and distal sides of the lower right first molar. Participants were instructed to rate the level of pain at T0 (before insertion), T1 (just after insertion), and T2 (24 hours after insertion) on a visual analog scale. The gingival crevicular fluid was collected at T0 and T2. The levels of anxiety, catastrophizing, tooth sensitivity, and cytokine expression were also assessed. Statistical analysis was performed with the Fisher-Freeman-Halton, chi-squared, Spearman's correlation, and dependent and independent t tests (α=5%). Pain intensity was higher at T2 than at T1, in both groups (P<.05). An association was established (P<.05) between pain intensity at T1 and catastrophizing, and at T2 with anxiety and catastrophizing. Within-group differences in cytokine expression were found between T0 and T2. There was no correlation between cytokine expression and pain levels, anxiety, catastrophizing, and sensitivity at T2. Tooth separation produced variable pain levels, which were influenced by anxiety and catastrophizing, however, pain level was not correlated with increased cytokine expression.

Psychological Profiles and Their Relevance with Temporomandibular Disorder Symptoms in Preorthodontic Patients

Background

Temporomandibular disorders (TMDs) refer to a group of heterogenous musculoskeletal diseases with diverse clinical symptoms and an undetermined aetiology. The psychological profiles were closely related to the onset and treatment outcomes of TMDs.

Objective

To examine the relevance between psychological profiles and different symptoms of TMDs in preorthodontic patients.

Methods

The study was conducted among 570 preorthodontic patients. TMDs symptoms were recorded by the Diagnostic Criteria for TMD (DC/TMD) symptom questionnaire. The seven-item Generalized Anxiety Disorder Scale (GAD-7), the nine-item Patient Health Questionnaire (PHQ-9), and the Pain Catastrophizing Scale (PCS) were used for the evaluation of anxiety, depression, and pain catastrophizing levels. The relevance of three psychological profiles with TMDs and subtypes was evaluated with Spearman's rank correlation test and logistic regression analysis (P < 0.05).

Results

34.56% of the enrolled preorthodontic patients were diagnosed with TMDs. Scores of GAD-7, PHQ-9, and PCS were significantly higher in the TMDs group than in the non-TMDs group. Participants with anxiety, depression, or high pain catastrophizing had a higher prevalence of both pain-related TMDs symptoms and intra-articular TMDs symptoms. The correlations among pain-related TMDs, intra-articular TMDs, and scores on the psychological scales were significant (P < 0.05). The adjusted logistic regression model revealed that anxiety, depression, and high pain catastrophizing were significant risk factors for TMDs with an odds ratio (OR) of 2.196, 1.741, and 1.601, respectively. Depression was associated with higher pain-related TMDs prevalence (OR = 2.136), while anxiety and depression were associated with higher intra-articular TMDs prevalence (OR = 2.341 and 1.473).

Conclusion

Anxiety, depression, and high pain catastrophizing were comorbid psychological conditions of TMDs. Depression was the top risk factor for pain-related TMDs, while anxiety rendered the highest risk for intra-articular TMDs. Inclusion of psychological assessments in preorthodontic evaluation might yield great benefits in TMDs screening.

Do different orthodontic pliers used in bracket debonding have different effects on pain and sensitivity? A prospective split-mouth study

OBJECTIVES

The assessment of whether different orthodontic pliers used in bracket debonding have different effects on pain and sensitivity experience.

MATERIALS AND METHODS

Thirty-three patients (17 females, 16 males) with metal brackets were included in the study. Compressed air and freshly melted ice water were applied to each tooth (6-6) in upper and lower arch before bracket debonding (T0), just after debonding (T1), and 1 week after debonding (T2). Bracket remover plier (BRP) and Weingart plier (WP) were used to debond brackets. A numeric rating scale (NRS) was used to assess sensitivity for each tooth at T0, T1, and T2. Tooth pain was assessed for each tooth using NRS during bracket debonding.

RESULTS

Statistically higher pain scores were found in teeth U4 (upper first premolar) (p = 0.017) and L6 (lower first molar) (p = 0.026) in Weingart plier group. No statistically significant difference was found during debonding in the other teeth between groups. Statistically high sensitivity score was found at T1 time point in tooth U3 (upper canine) by applying air stimulus in Weingart plier group (p = 0.024). There was no statistically significant difference between the sensitivity scores measured at T2 time point by applying air and cold stimuli between groups.

CONCLUSIONS

Although the debonding pain scores were statistically significant in two teeth and the sensitivity score in one tooth, there was no clinical significance between the two pliers in terms of pain and sensitivity.

CLINICAL RELEVANCE

Both debonding pliers gave clinically similar results in terms of pain and sensitivity.

Association of oral behaviours' frequency with psychological profile, somatosensory amplification, presence of pain and self-reported pain intensity

OBJECTIVE

To investigate the association of the frequency of oral behaviours with psychological (anxiety, depression) and psychosomatic factors (somatosensory amplification) as well as with pain presence (Temporomandibular disorders-pain (TMDp) patients and control (CTR) participants) and pain intensity (no_low pain intensity (nLPI)/high pain intensity (HPI)).

MATERIAL AND METHODS

Fifty-four TMDp patients (48 females and 6 males; 29.13 ± 10.46 years) and 46 controls (29 females and 17 males; 28.54 ± 9.71 years) were administered Oral Behaviours Checklist (OBC), Generalized Anxiety Disorder-7 Scale, Patient Health Questionnaire-9 for depression and Somatosensory Amplification Scale. Data were analysed with respect to the presence of TMD pain and to pain intensity. Mann-Whitney test and Spearman's rank correlation were used for analyses.

RESULTS

No significant differences in examined variables between TMDp patients and CTR individuals were found. The frequency of oral behaviors (OBC total score and sleep-related oral behaviours) as well as anxiety, depression and somatosensory amplification scores were higher in HPI group when compared to nLPI group (p < .05). In univariate correlations, oral behaviours were positively correlated with somatosensory amplification (p = .001), anxiety (p < .05), depression (p < .05), female sex (p < .05) and pain intensity (p < .05) but not with pain presence. Multiple linear regression models showed that predictors for the higher frequency of oral behaviours were anxiety and female sex.

CONCLUSIONS

Oral behaviours were associated with pain intensity but not with pain presence and were primarily influenced by anxiety and female sex, suggesting that therapeutic approach should consider both, reducing pain intensity and management of the impact of psychological factors.Trial registration: ClinicalTrials.gov NCT04694274. Registered on 01/04/2021.

Effects of acute pain and strain of the periodontium due to orthodontic separation on the occlusal tactile acuity of healthy individuals

OBJECTIVES

The aim of this study was to assess whether pain and strain of the periodontal ligament (PDL), induced by orthodontic separation, alter the somatosensory ability to perceive small thicknesses between occluding teeth (occlusal tactile acuity, OTA).

METHODS

The OTA was tested at baseline (T0), using 9 aluminum foils (range 8-72 μm), randomly placed between the molar teeth, and 1 sham test (without foil), asking the participants whether they felt the foil between their teeth. Afterwards, orthodontic separators were placed, and subjects were randomly assigned to one of the two experimental groups: Group Pain (GP: 18 males; 14 females mean age 25.22 ± 2.28 years) had separators removed after 24 h; Group Strain (GS: 14 males; 17 females, mean age 24.03 ± 3.06 years) had separators removed after 7 days. The OTA measurement was repeated in both groups immediately after orthodontic separators removal (T1). A within-group comparison (T1 vs T0) was performed for each testing thickness (ANOVA for repeated measurements, with Bonferroni correction for multiple testing) (p < 0.005).

RESULTS

GP showed statistically significant reduction of the OTA at T1, as compared to T0, for the thicknesses 24 μm (p = 0.004) and 32 μm (p = 0.001). No significant reduction was observed in GS (all p > 0.005).

CONCLUSIONS

Acute periodontal pain tends to disturb the tactile ability of the teeth, while strain of the PDL in absence of painful sensation determines a return to OTA baseline values.

CLINICAL RELEVANCE

The reduction of OTA might explain the uncomfortable occlusal sensation referred by patients during acute periodontal pain.

Is catastrophizing associated with pain perception in early phase of orthodontic treatment? a cohort study

BACKGROUND AND OBJECTIVES

This study aimed to investigate the association between pain perception and catastrophizing at the beginning of orthodontic treatment; and the association between pain during orthodontic treatment and demographic, clinical, and other psychological factors.

METHODS

A cohort study with 44 patients (28.9±15.05 years old; 25 females and 19 males) under orthodontic treatment with fixed appliances had their pain perception evaluated through a visual analog scale at baseline (before activation), 6 h, 24 h, 2^nd day, 3^rd day, 5^th day, and 7^th day after activation. The scores at each evaluation period after the first (T1), second (T2), and third (T3) appointments were compared by analysis of variance. A multivariate Poisson regression analysis verified the association between pain perception and Pain Catastrophizing Scale (PCS); and demographic (age, gender), clinical (tooth crowding, tooth loss, analgesic intake, and archwire characteristics), and other psychological (dental anxiety, and previous negative dental experiences) independent variables (p<.05).

RESULTS

Catastrophizing (RR=1.03, 95%CI 1.01 to 1.05, p=.0001) showed a weak risk of pain perception at T1. The peak of pain occurred 24 h after activation at T1, T2, and T3. Significant higher scores were observed at T1 in comparison to T2 (F_T1,T2 =11.82, p=.005) and T3 (F_T1,T3 =5.09, p=.03). Wire diameter, tooth crowding, and single arch treatment were found as risk factors for pain. Patients without tooth loss had half of the risk of pain perception, while analgesics intake and older patients were also found with a weak protective association. Dental anxiety and negative dental experience were not associated with pain perception.

CONCLUSION

Catastrophizing has a mild influence on pain perception and only after the first orthodontic activation. Patients with tooth losses, tooth crowding, and using thicker archwires are more likely to report pain after orthodontic activations.

Molecular mechanism in trigeminal nerve and treatment methods related to orthodontic pain

BACKGROUND

Orthodontic treatment is the main treatment approach for malocclusion. Orthodontic pain is an inevitable undesirable adverse reaction during orthodontic treatment. It is reported orthodontic pain has become one of the most common reason that patients withdraw from orthodontic treatment. Therefore, understanding the underlying mechanism and finding treatment of orthodontic pain are in urgent need.

AIMS

This article aims to sort out the mechanisms and treatments of orthodontic pain, hoping to provide some ideas for future orthodontic pain relief.

MATERIALS

Tooth movement will cause local inflammation. Certain inflammatory factors and cytokines stimulating the trigeminal nerve and further generating pain perception, as well as drugs and molecular targeted therapy blocking nerve conduction pathways, will be reviewed in this article.

METHOD

We review and summaries current studies related to molecular mechanisms and treatment approaches in orthodontic pain control.

RESULTS

Orthodontics pain related influencing factors and molecular mechanisms has been introduced. Commonly used clinical methods in orthodontic pain control has been evaluated.

DISCUSSION

With the clarification of more molecular mechanisms, the direction of orthodontic pain treatment will shift to targeted drugs.

Influence of functional and esthetic expectations on orthodontic pain

OBJECTIVES

To investigate the effect of orthodontic treatment outcome (OTO) expectations on the level of pain intensity experienced after orthodontic elastomeric separation (OES).

MATERIALS AND METHODS

A total of 100 orthodontic patients (74 female and 26 male, age 14 years and above) from the Faculty of Dentistry, Mahidol University were enrolled. Before OES, questionnaires were administered to obtain patients' expectations regarding various aspects of OTO as well as OES pain expectations. Real-time self-reported pain intensity from OES at the maxillary and mandibular first permanent molars was obtained before and immediately after separator placement and at 6 h, 24 h, and then every day until day 7 after OES. Data were analyzed for the relationship between OTO expectations and OES pain intensity. The level of significance was set at 0.05.

RESULTS

The maximum OES pain intensity occurred on day 2 after OES and gradually decreased to the pretreatment level on day 7. The degree of facial, tooth alignment, masticatory function improvement expectations, and a high level of OES pain expectations were significantly associated with the severity of OES pain after separator placement.

CONCLUSION

Esthetic and functional expectations of OTO were significantly associated with OES pain intensity. Thus, knowledge about esthetic and functional expectations may help to predict patient's pain response to orthodontic treatment.

Comparison of pain perception, anxiety, and impacts on oral health-related quality of life between patients receiving clear aligners and fixed appliances during the initial stage of orthodontic treatment

BACKGROUND AND OBJECTIVES

Clear aligner is an advanced orthodontic method with benefits of comfort, aesthetics, and convenience. This study aimed to compare pain perception, anxiety, and impacts on oral health-related quality of life (OHRQoL) between adult patients receiving clear aligners and fixed appliances during the initial stage of orthodontic treatments.

MATERIAL AND METHODS

The two groups were well matched by ages, gender, and levels of malocclusion severity. Pain perception, anxiety, and OHRQoL were assessed through visual analogue scale, state-trait anxiety inventory, and oral health impact profile-14 (OHIP-14), respectively. And the comparison of above scores was performed by two-way analysis of variance.

RESULTS

A total of 110 patients (55 pairs) were enrolled in this study. Orthodontic pain levels peaked on the first day and decreased gradually afterwards in both groups, which were significantly higher in the fixed group on the first, second, fourth, and fifth days. Likewise, anxiety levels peaked on the first day and decreased thereafter, with significant difference on the 1st, 3d, 5th, 7th, and 14th days. Moreover, the OHIP-14 scores increased and peaked on the first day and then gradually decreased for both groups, which were also significantly higher in the fixed group on the 1st, 7th, and 14th days.

LIMITATIONS

More malocclusion types should be used for group matching. The effect of exclusion of small groups should be taken into consideration in sample size calculation. Income was significantly unbalanced between two groups due to higher cost of clear aligners, and random assignment of treatment modalities was unfeasible.

CONCLUSIONS

Patients treated with clear aligners experienced lower pain levels, less anxiety, and higher OHRQoL as compared to those receiving fixed appliances.

Perception of pain in Class II malocclusion children treated with cervical headgear: a randomized controlled trial

OBJECTIVES

The aims of this study were: 1. to evaluate the experience of pain perceived by children during separator placement and headgear wear; 2. to find possible associations between the perceived intensity of pain and the levels of Substance P (SP) and interleukin-1 beta (IL-1β) in the gingival crevicular fluid (GCF) during these procedures; 3. to identify other factors, such as previous pain experience, which could be associated to the patients' perceived discomfort or pain during treatment.

TRIAL DESIGN

Nine-month parallel-group randomized controlled trial.

METHODS

Forty Class II malocclusion children (8-12 years) were included, half of which received a cervical headgear while the other half did not receive any treatment during the study period. Baseline pain data were recorded including previous experience to general and dental pain, Corah's Dental Anxiety Scale, and baseline pain using a visual analogue scale (VAS). Elastic separators were placed in children for 1 week, followed by molar band and cervical headgear placement. Children were seen at various time points throughout the 9-month period where at each appointment, a VAS assessment of pain as well as GCF sampling was carried out to quantify the levels of SP and IL-1β. Multiple regression analysis was performed to ascertain the influence of factors including sex, age, time, headgear wear, and baseline pain data on pain severity.

RESULTS

Pain severity and SP and IL-1β levels in the GCF follow a similar pattern, with peaks being observed 1 day after orthodontic elastic separator placement. Pain was more severe after the placement of orthodontic separators than following cervical headgear wear. With regard to pain predictors, pain is more severe in older children, those with a worse previous general pain experience, and those with higher levels of IL-1β, particularly after elastic separator placement.

CONCLUSIONS

Orthodontic pain and discomfort following orthodontic separator placement and cervical headgear wear depends on factors including age, previous pain experience, and the level of IL-1β in the GCF.

Comparative Evaluation of Different Numerical Pain Scales Used for Pain Estimation during Debonding of Orthodontic Brackets

Introduction

Patients experience various levels of discomfort during orthodontic treatment, i.e., after placement of separators, orthodontic implant placement, and archwire placement and during debonding. Various pain control methods have been developed to relive pain during debonding, i.e., finger pressure (FP), elastomeric wafer (EW), and stress relief (SR).

Aim

To analyse various pain scales commonly used to determine the effect of different pain control methods during debonding of orthodontic brackets. Study Design. A comparative cross-sectional study performed on a sample of 60 patients (n = 60) including 14 males and 46 females who were ready for debonding and who were divided into three groups, i.e., finger pressure (FP), elastomeric wafer (EW), and stress relief (SR).

Materials and Methods

A 100 mm Visual Analog Scale (VAS) was used to record the pain intensity for each tooth. Another scale known as Pain Catastrophizing Scale (PCS) was used to evaluate the patient's general attitude towards pain perception. The armamentarium and operator were kept same for all the patients. Statistical analysis used was the Kruskal-Wallis test, used for intergroup and intragroup comparison of pain scores.

Results

Lowest total pain score was recorded in the FP group (P=0.043) on intergroup comparison, while on intragroup comparison, higher pain scores were recorded in lower anterior region (P=0.02) in all three groups. There was no significant difference between the pain scores reported by the male and female subjects.

Conclusion

FP is an effective method of pain control. And teeth in the anterior region of lower and upper arches are more sensitive to pain. In terms of cognitive-affective constructs, although the VAS has been widely used in previous studies, the PCS has been detailed to show the most reliable association with physical discomfort and emotional distress.

The influence of text messages and anxiety on pain perception and its impact on orthodontic patients routine

OBJECTIVE

This prospective study aimed at assessing the effects of anxiety and a follow-up text message on pain perception after the installation of fixed orthodontic appliances and its impact on the patients' routine.

METHODS

The sample of this study consisted of 103 orthodontic patients, 40 males and 63 females (mean age 20.5 years), distributed in two groups: G1 (n=51), including control patients that did not receive any post-procedure communication; and G2 (n=52), including patients that received a structured text message. In baseline phase, the patients completed a questionnaire to assess their level of anxiety prior to treatment. Pain was assessed by using 100-mm visual analog scale (VAS) in baseline and ten times prospectively in predetermined time points. VAS was also applied to assess the patient's routine alterations caused by the pain. All data were analyzed using ANOVA, Tukey, Mann-Whitney, t-test, chi-square and Spearman's correlation tests. All statistical tests were performed with significance level of 5%.

RESULTS

Low-level and high-level anxiety was observed in 42.7% and 7.8% of the patients, respectively. Statistically significant correlation was observed between anxiety and pain (p< 0.05). Maximum mean pain intensity was detected in the second treatment day (G1=36.9mm and G2=26.2mm) and was significantly higher in G1. Nearly 53% of the patients in G1 reported alterations in the routine (18.8mm), while in G2 the percentage rate reached 28.8% (9.9mm) (p=0.013).

CONCLUSIONS

Anxious patients report more pain after the installation of orthodontic appliances. Text messages were effective to reduce pain levels and to decrease the negative effects on patients' daily routine.

Evaluation of pain intensity in patients treated with aligners and conventional fixed appliances: Randomized clinical trial

OBJECTIVE

This randomized clinical trial aimed to compare the pain intensity in patients treated with orthodontic aligners and conventional fixed appliances.

SETTING AND SAMPLE POPULATION

This study was a randomized clinical trial. The sample comprised 39 patients randomly allocated into 2 groups: OA (orthodontic aligners, n = 20) and FA (Fixed Appliance, n = 19).

MATERIAL AND METHODS

The pain intensity was measured by the visual analogue scale (VAS) in the following periods: T0 (baseline), T1 (seven days after appliance placement) and seven days after each return on the first (T2), third (T3) and sixth (T4) months. The following variables were also investigated in the baseline: conditioned pain modulation, anxiety levels, hypervigilance and catastrophizing. The VAS measurements between groups were compared by the Mann-Whitney test. Comparisons between periods within each group were performed by the Friedman test. Data regarding catastrophizing and hypervigilance were compared by the t test. All tests were applied at a significance level of 5%, with 95% confidence interval.

RESULTS

Both groups presented similar levels of anxiety, hypervigilance, catastrophizing and conditioned pain modulation. Both groups did not differ concerning the pain intensity in all periods. The intragroup evaluation revealed statistical differences between days in the FA group at all moments evaluated, for the OA group, similar findings between days were found for the T1 evaluation; however, at the 6-month period (T4), the pain levels varied over these days without statistical difference. Higher levels of pain were observed in the first seven days after appliance placement.

CONCLUSION

The pain intensity, usually mild, was not influenced by the appliance design, although different patterns of reported pain seem to occur between groups.

Increased somatosensory amplification is associated with decreased pressure pain thresholds at both trigeminal and extra-trigeminal locations in healthy individuals

BACKGROUND

The diagnosis of temporomandibular disorders (TMD) is based on patient history and physical examination, and may require medical imaging. Masticatory muscle palpation is essential to make a diagnosis of TMD. However, the response of masticatory muscles to mechanical pressure stimuli depends on many physical and psychological factors.

OBJECTIVE

This study aimed at determining the impact of somatosensory amplification (SSA)-an estimate of somatic awareness and bodily hypervigilance-on pressure pain thresholds (PPTs) measured at both trigeminal and extra-trigeminal locations in healthy individuals.

METHODS

PPTs were measured at the right anterior temporalis and superficial masseter, and the thenar eminence of the right hand in one hundred healhty individuals (69F, 31M), divided in three groups based on their SSA scores: low (N = 32), intermediate (N = 34) and high (N = 34). General linear models were used to test between-group differences in PPTs including sex as a covariate. The level of significance was set at P < .05.

RESULTS

Individuals with high SSA had lower PPTs at the anterior temporalis than individuals with low (P = .006) and intermediate (P = .001) SSA. No significant between-group differences were found in PPTs measured at the masseter (P = .372). PPTs measured at the thenar eminence were significantly lower in the high than the low SSA group (P = .009). Females had lower PPTs at the masseter than males (P = .021) but not at other muscle locations (all P > .05).

CONCLUSION

Increased somatosensory amplification is associated with decreased pressure pain thresholds at both trigeminal and extra-trigeminal locations in healthy individuals. SSA could be a potential confounder while diagnosing TMD and evaluating treatment outcomes.

Impact of clear aligner therapy on tooth pain and masticatory muscle soreness

BACKGROUND

Clinical findings suggest that orthodontic treatment with clear aligners (clear aligner therapy/CAT) may cause masticatory muscle soreness in some patients.

OBJECTIVE

This multi-site prospective study investigated tooth pain and masticatory muscle soreness and tenderness in patients undergoing CAT and explored whether psychological traits affected these outcomes.

METHODS

Twenty-seven adults (22F, 5M; mean age ± SD=35.3 ± 17.6 years) about to start CAT were recruited at three clinics. During CAT, they reported on 100-mm visual analogue scales their tooth pain, masticatory muscle soreness and stress three times per day over 4 weeks (week 1 = baseline; week 2 = dummy aligner; week 3 = first active aligner; week 4 = second active aligner). Pressure pain thresholds (PPTs) were measured at the masseter and temporalis at baseline and after week 4. Mixed models were used to evaluate the outcome measures over time.

RESULTS

Clear aligner therapy caused mild tooth pain, which was greater with the passive than the first and second active aligners (both P < .001). Mild and clinically not relevant masticatory muscle soreness was produced by all aligners (all P < .05), with the first active aligner producing less soreness than the dummy aligner (P < .001). PPTs did not change significantly after 4 weeks. Both tooth pain and masticatory muscle soreness were affected by stress and trait anxiety, whilst muscle soreness was affected also by oral behaviours.

CONCLUSIONS

In the short term, CAT produces tooth pain and masticatory muscle soreness of limited significance. Frequent oral behaviours are related to increased masticatory muscle soreness during CAT. The medium- and long-term effects of CAT should be further explored.

Impact of catastrophizing on pain during orthodontic treatment

Objective:

This study proposed to investigate the influence of catastrophizing and others factors related to pain during orthodontic treatment.

Methods:

27 patients with 0.022 x 0.028-in Straight-wire brackets were evaluated during alignment and leveling phase with nickel-titanium wires. Visual Analog Scales measured the intensity of orthodontic pain at six moments after a clinical appointment: 6 first hours; 1, 2, 3, 5, and 7 days. Multiple linear regression and stepwise approach assessed the influence of the following variables on pain: catastrophizing, sex, age, duration of treatment, clinical appointment time (morning or afternoon), and wire diameter.

Results:

The highest pain intensity was reported 24 hours after activation. These data were used to analyze factors associated with pain level. Age (r = 0.062, p= 0.7586), sex (p= 0.28), catastrophizing (r = -0.268, p= 0.1765), and orthodontic wire diameter (r = 0.0245, p= 0.2181) were not correlated with orthodontic pain in the univariate statistics. Catastrophizing was included in the multiple regression model because it was of great interest. Duration of orthodontic treatment (r = 0.6045, p= 0.0008) and the time when orthodontic appliance was activated (p= 0.0106) showed statistical significant associations with pain, and were also included in the multivariate regression, which showed that about 32% of orthodontic pain could be explained by the duration of treatment (R²= 0.32, p= 0.0475). Catastrophizing (R²= 0.0006, p= 0.8881) and clinical appointment time were not significantly associated with pain (R²= 0.037, p= 0.2710).

Conclusions:

Pain after activation of fixed orthodontic appliance is not associated with catastrophizing as well as age, sex, orthodontic wire diameter, and period of activation.

Chewing gum vs. ibuprofen in the management of orthodontic pain, a multi-centre randomised controlled trial - the effect of anxiety

OBJECTIVES

Pain is a common side effect of orthodontic treatment. An objective of this study, part of a large previously reported RCT on pain and analgesic use, was to determine the effect of anxiety on perceived pain and use of analgesia.

METHODS

1000 patients aged 11-17 years, undergoing upper and lower fixed appliance treatment in nine hospital departments were recruited into this two-arm parallel design randomised controlled trial. One arm was given sugar-free chewing gum and the other arm ibuprofen for pain relief. Neither the clinicians nor patients were blinded to assignment. In addition to recording pain experience and analgesic use for 3 days following appliance placement and first archwire change, each patient recorded their level of anxiety immediately following the fitting of the appliance and the first archwire change.

RESULTS

419 chewing gum group (84%) and 407 ibuprofen group (83%) questionnaires were returned following appliance placement, and 343 chewing gum group (70%) and 341 ibuprofen group (71%) questionnaires were returned following the first archwire change. The mean anxiety scores following fitting of the appliance and first archwire change were 2.7 (SD 2.1) and 1.6 (SD 1.8), respectively. There were weak but significant positive associations between anxiety scores and pain scores. Multi-level modelling produced a coefficient for anxiety of 0.23 (95% CI 0.17-0.28) for appliance placement, suggesting a small rise (0.23) on the 11-point pain scale for a one-point increase on the corresponding anxiety scale. Following archwire change, the corresponding coefficient was 0.32 (0.24-0.39). For ibuprofen use, again simple analyses suggested a relationship with anxiety. Multi-level logistic modelling produced an odds ratio for ibuprofen use of 1.11 (95% CI 1.07-1.15) at appliance placement and 1.21 (1.10-1.33) at the first archwire change. There was a 10-20% increase in the odds of using ibuprofen for each one-point increase on the anxiety scale. No such relationship was found between anxiety and chewing gum use. There were no adverse effects or harms reported during the trial. Approvals were granted by the Research Ethics Committee (08/H0106/139), R&D and MHRA (Eudract 2008-005522-36) and the trial was registered on the ISRCTN (79884739) and NIHR (6631) portfolios. Support was provided by the British Orthodontic Society Foundation.

CONCLUSIONS

There was a weak positive correlation between anxiety reported and pain experienced following both the initial fitting of the fixed appliances and at the subsequent archwire change. Patients that were more anxious tended to take more ibuprofen for their pain relief.

Separation and pain perception of Elastomeric, Kesling and Kansal separators

Introduction:

Various types of separators have been advocated, but the ideal separator should produce optimum separation with minimal pain and discomfort.

Objective:

The objective of this study was to evaluate and compare the amount of separation achieved by three different types of separators (Elastomeric, Kesling and Kansal), and to assess the associated pain and discomfort.

Methods:

A random single-blind split-mouth study was conducted on 108 patients seeking fixed orthodontic treatment, in which two different separators were used on each side in both the arches for a single patient. After five days, the amount of separation was measured with a feeler gauge. Visual Analogue Scale (VAS) scoring was performed by the patient on each day, to evaluate pain perception. Discomfort was evaluated by questionnaire filled by the patient at the time of separator removal.

Results:

The greatest amount of separation was seen with the elastomeric separators, while the smallest separation was seen with Kansal separators. VAS scoring showed maximum pain at day 1 with all the three separator types. Highest pain was perceived in the Elastomeric separators group, followed by Kesling and Kansal separators, respectively. Statistically significant difference was found in VAS score of Elastomeric separators, when compared to both Kesling and Kansal, on day 1 and 2 (p= 0.001). Analysis of the questionnaires revealed that a greater number of patients experienced discomfort with elastomeric separators placement (69.4%), which was statistically significant (p< 0.01) when compared to the other two types of separators. Answers to the other questions were comparable, except for the need for medications, which was reportedly highest with elastomeric separators.

Conclusion:

Kesling separators produce adequate separation with minimal discomfort and pain, compared to Elastomeric and Kansal separators.

The effect of a lidocaine/prilocaine topical anesthetic on pain and discomfort associated with orthodontic elastomeric separator placement

Background

The initial placement of orthodontic elastomeric separators can be uncomfortable and painful. Therefore, it is important to relieve this disturbing sensation to create a discomfort or pain-free orthodontic visit. The purpose of this study was to investigate the effect of a lidocaine/prilocaine topical anesthetic on pain and discomfort associated with the placement of orthodontic elastomeric separators.

Methods

Fifty subjects aging between 20–35 years were included in this study. In the maxillary arch, a lidocaine/prilocaine topical anesthetic was placed around the ginigval margins of the premolar and molar on side. On the other side, a placebo agent was placed around the ginigval margins of the premolar and molar. After two minutes, an elastomeric separator was placed between the premolar and molar on both sides. The subjects were then asked to report their findings on a Verbal Scale and a Visual Analogue Scale every second minute for a period of 10 min. The subjects were also given a questionnaire to evaluate the overall impression on the topical anesthetic use.

Results

The overall mean discomfort/pain score was found to be significantly lower (p < 0.001) with the topical anesthetic than with the placebo. Repeated measures ANOVA with a Greenhouse-Geisser correction determined that mean pain scores were statistically significantly low with the 10-min time duration (F_(1.54,42.2) = 40.7, p = 0.001), with an estimated grand mean (8.37, 95% CI 6.75–9.98). The questionnaire responses revealed that 87% of the subjects reported an overall satisfaction and agreement with the topical anesthetic than with the placebo or no difference (13%) after the initial separator placement.

Conclusions

The discomfort and pain resulting from the initial placement of orthodontic elastomeric separators can be significantly reduced with the lidocaine/prilocaine topical anesthetic.

Pain and distress induced by elastomeric and spring separators in patients undergoing orthodontic treatment

Aims and Objectives:

The objective of the present investigation is to evaluate patients’ pain perception and discomfort, the duration of pain and the level of self-medication over time during tooth separation, and the effectiveness of elastomeric and spring types of orthodontic separators in Saudi population.

Materials and Methods:

The study group consisted of 30 female adolescent patients who had elastomeric/spring separators as part of their orthodontic treatment. A self-administrated questionnaire comprising 16 multiple choice questions and another with visual analog scale were used to record the patient's pain perceptions at 4 hours, 24 hours, 3 days, 5 days, and 7 days from the time of insertion. The level of pain and discomfort during these time periods were assessed by a visual analog scale. After a separation period of 7 days, the amount of separation was measured with a leaf gauge. Type and frequency of analgesic consumption was also recorded. The Statistical Package for the Social Sciences (SPSS) version 20 (IBM SPSS -Chicago, IL: SPSS Inc.,) was used for statistical analysis.

Results:

The data showed significant increase in the level of pain at 4 hours, 24 hours, and 3 days from separator placement. The elastomeric separators produced significantly more separation than the spring separators and also caused maximum pain during the first 3 days after insertion. However, there was no significant difference between the score of pain between two separators at all time intervals.

Conclusion:

Both elastomeric and spring separators showed comparative levels of pain and discomfort during the early phase of separation. Elastomeric separators were found to be more effective in tooth separation than spring separators. However, further studies are necessary to substantiate this preliminary observation.

Current advances in orthodontic pain

Orthodontic pain is an inflammatory pain that is initiated by orthodontic force-induced vascular occlusion followed by a cascade of inflammatory responses, including vascular changes, the recruitment of inflammatory and immune cells, and the release of neurogenic and pro-inflammatory mediators. Ultimately, endogenous analgesic mechanisms check the inflammatory response and the sensation of pain subsides. The orthodontic pain signal, once received by periodontal sensory endings, reaches the sensory cortex for pain perception through three-order neurons: the trigeminal neuron at the trigeminal ganglia, the trigeminal nucleus caudalis at the medulla oblongata and the ventroposterior nucleus at the thalamus. Many brain areas participate in the emotion, cognition and memory of orthodontic pain, including the insular cortex, amygdala, hippocampus, locus coeruleus and hypothalamus. A built-in analgesic neural pathway—periaqueductal grey and dorsal raphe—has an important role in alleviating orthodontic pain. Currently, several treatment modalities have been applied for the relief of orthodontic pain, including pharmacological, mechanical and behavioural approaches and low-level laser therapy. The effectiveness of nonsteroidal anti-inflammatory drugs for pain relief has been validated, but its effects on tooth movement are controversial. However, more studies are needed to verify the effectiveness of other modalities. Furthermore, gene therapy is a novel, viable and promising modality for alleviating orthodontic pain in the future.

Efficacy of different methods to reduce pain during debonding of orthodontic brackets

OBJECTIVE

To determine pain during debonding and the effects of different pain control methods, gender, and personal traits on the pain experience.

MATERIALS AND METHODS

Patients who had fixed orthodontic treatment with metal brackets, but no surgical treatment or craniofacial deformity, were included. Sixty-three patients (32 female, aged 17.2 ± 2.9 years; 31 male aged, 17.2 ± 2.5 years) were allocated to three groups (n = 21) according to the pain control method: finger pressure, elastomeric wafer, or stress relief. Pain experience for each tooth was scored on a visual analogue scale (VAS), and general responses of participants to pain were evaluated by Pain Catastrophizing Scale (PCS). Multiple linear regression analysis, the Mann Whitney U-test, and Spearman's rank correlation coefficient analysis were used to analyze the data.

RESULTS

When the VAS scores were adjusted, finger pressure caused a 47% reduction overall, 56% in lower elastomer wafer total, 59% in lower right arch, 62% in lower left, and 62% in lower anterior compared with the elastomeric wafer. In the elastomer wafer group, upper and lower anterior scores were higher than posterior scores, respectively. Females had higher VAS (lower left and anterior) and total PCS scores than males. Regardless of the pain control method, total PCS scores were correlated with total (r = .254), upper total (r = .290), right (r = .258), left (r = .244), and posterior (r = .278) VAS scores.

CONCLUSIONS

The stress relief method showed no difference when compared with the other groups. Finger pressure was more effective than the elastomeric wafer in the lower jaw. Higher pain levels were recorded for the anterior regions with the elastomeric wafer. Females and pain catastrophizers gave higher VAS scores.

Intensity of pain due to separators in adolescent orthodontic patients

Objective:

To investigate the intensity of pain adolescent orthodontic patients experience following the insertion of separators.

Materials and Methods:

Elastomeric separators were placed mesially and distally to the first molars in 62 adolescents (20 male, 42 female, age 12–15 years), and the participants were given self-administrated questionnaires to document perceived pain, pain upon chewing, and the severity of pain's affecting daily life, using a visual analog scale for seven days.

Results:

The mean perceived pain scores out of 100 on the first 3 days were 54.6 ± 32.7, 51.7 ± 29.9, and 32.3 ± 28.4, respectively; chewing pain scores were: 61.9 ± 35.3, 52.6 ± 30.4, and 39.5 ± 32.1, respectively; the pain's affecting daily life scores were 24.9 ± 35.5, 21.1 ± 30.9, and 11.9 ± 23.7, respectively. A Kruskal–Wallis test showed a statistically significant difference in the reported pain between the three studied parameters. A Mann–Whitney U-test showed an insignificant difference between male and female adolescents.

Conclusion:

Pain perception varies among adolescent patients, but it decreases significantly after the first 2 days, with no gender differences.

Effect of somatosensory amplification and trait anxiety on experimentally induced orthodontic pain

The perception of pain varies considerably across individuals and is affected by psychological traits. This study aimed to investigate the combined effects of somatosensory amplification and trait anxiety on orthodontic pain. Five-hundred and five adults completed the State Trait Anxiety Inventory (STAI) and the Somatosensory Amplification Scale (SSAS). Individuals with combined STAI and SSAS scores below the 20th percentile (LASA group: five men and 12 women; mean age ± SD = 22.4 ± 1.3 yr) or above the 80th percentile (HASA group: 13 men and seven women; mean age ± SD = 23.7 ± 1.0 yr) were selected and filled in the Oral Behaviors Checklist (OBC). Orthodontic separators were placed for 5 d in order to induce experimental pain. Visual analog scales (VAS) were administered to collect ratings for occlusal discomfort, pain, and perceived stress. Pressure pain thresholds (PPT) were measured. A mixed regression model was used to evaluate pain and discomfort ratings over the 5-d duration of the study. At baseline, the LASA group had statistically significantly higher PPT values for the masseter muscle than did the HASA group. During the experimental procedure, the HASA group had statistically significantly higher discomfort and pain. A significant difference in pain ratings during the 5 d of the study was found for subjects in the HASA group. Higher OBC values were statistically significantly positively associated with pain. Somatosensory amplification and trait anxiety substantially affect experimentally induced orthodontic pain.

Fixed orthodontic appliances cause pain and disturbance in somatosensory function

This study aimed to assess the short-term effects of orthodontic pain on quantitative sensory testing (QST) in subjects receiving fixed orthodontic treatment. Twenty patients and 12 healthy volunteers (as controls) participated. All 20 patients had bonded AO self-ligating brackets, with a 0.014 super elastic nickel-titanium arch wire placed in the brackets. Pain [self-reported on a visual analog scale (VAS)], and thermal and mechanical thresholds, were tested at six time points--before (baseline), and 2 h, 24 h, 7 d, 14 d, and 30 d after, force application--in the treatment group. The attached gingiva adjacent to the left upper central incisor (21 gingiva) was hypersensitive to cold stimuli (i.e. increased cold detection thresholds were detected) in the treatment group. The pressure pain thresholds of the left upper central incisor (21) and 21 gingiva were significantly reduced. Our results suggest clear signs of sensitization of the trigeminal nociceptive system up to 1 month after force application and orthodontic pain. Quantitative assessment of somatosensory function may help to provide a better understanding and profiling of the underlying neurobiological mechanisms related to orthodontic pain.