Changes in ability of patients to differentiate intensity of forces applied to maxillary central incisors during orthodontic treatment

Orthodontic Pain and Dietary Impact Considering Age Groups: A Comparative Study

(1) Background: orthodontic treatment can frequently be associated with discomfort and pain, a significant factor contributing to treatment discontinuation. (2) Methods: This study, conducted on 160 orthodontic patients across different age groups, aimed to explore the influence of age on patients' responses to treatment, particularly regarding changes in dietary patterns and weight loss. The patients were categorized into three age groups and assessed through a questionnaire about pain perception, pain latency, dietary changes, and weight loss associated with orthodontic appliances. (3) Results: Younger patients (6-12 years) reported lower pain levels, shorter pain latency and fewer alterations in dietary habits compared to adults (over 18 years). Females over 18 represented a significant portion of the sample, suggesting a self-driven inclination towards orthodontic treatment for aesthetic reasons. Fixed orthodontic appliances induced more significant pain than removable ones. Adults experienced more changes in dietary habits and weight loss than younger individuals. (4) Conclusions: the results provide valuable insights for orthodontic practitioners aiming to mitigate adverse effects and improve overall patient experience during treatment.

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.

Perceived pain for orthodontic patients with conventional brackets or self-ligating brackets over 1 month period: A single-center, randomized controlled clinical trial

BACKGROUND/PURPOSE

The objective of this 2-arm parallel trial was to test the superiority of self-ligating brackets (SLB) over conventional brackets (CB) in terms of perceived pain for orthodontic patients.

METHODS

Patients about to undergo treatment were included to fixed appliance placed with CB or SLB. Eligibility criteria included malocclusion patients whose age between 12 to 40 years and suitable for orthodontic fixed appliance treatment. The main outcome was pain intensity measured by visual analog scale (VAS) with all patients followed at 4 h, 24 h, 3 days, 1 week and 1 month. Randomization was accomplished with a computer-generated list of random numbers. Blinding was applicable for outcome assessment only. Data were analyzed using multi-level nonlinear mixed effect model, Friedman's test and Wilcoxon signed rank test with the Bonferroni correction for multiple tests.

RESULTS

Eight-eight patients were randomized in a 1:1 ratio to either SLB or CB. All patients completed the study, and none were lost to follow-up. There were no drop-outs after randomization. Baseline characteristics were similar between groups. The is no statistical significant difference in pain intensity between CB and SLB at 4 h, 24 h, 3 days, 1 week and 1 month. Data were analyzed on an intention-to-treat basis. No serious harm was observed.

CONCLUSION

The results of this study indicated no evidence that the pain intensity differs between CB and SLB at 4 h, 24 h, 3 days, 1 week and 1 month.

Comparison of the Perception of Pain during Fixed Orthodontic Treatment with Metal and Ceramic Brackets

Introduction:

Pain is experienced by patients during various fixed orthodontic procedures such as placement of separators, insertion of arch wire and its activations, orthopedic appliances such as headgear, and debonding of the appliance. This study was formulated with the background that the level of pain sensation differs between conventional metal and ceramic brackets, arch wire being the same.

Materials and Methods:

The sample comprised 40 patients. The patients were separated into two groups: Group A (metal brackets) and Group B (ceramic brackets). In Group A, the brackets were bonded with 0.022” conventional stainless steel brackets (Unitek Gemini, 3M, Monrovia, California). In Group B, the brackets were bonded with ceramic brackets (Unitek Gemini Clear Brackets, 3M, Monrovia, California). The bonding of the brackets was carried out according to the conventional etching, priming, and curing technique. A 0.016” NiTi (nickel titanium) arch wire was used as the first arch wire. The intensity of pain was documented in a figure containing two 100-mm visual analog scales (VASs).

Results:

The level of pain reduced in intensity in due course. During 1 month, VAS scores increased at the end of day 1 (24 h) for the metal and ceramic group. The pain then decreased for up to 5 days. The average pain intensity reached 4.44 in the ceramic group, whereas it was 2.7 in the metal group for the upper anterior region. It decreased up to 1 in the ceramic and 0.22 in the metal group.

Conclusion:

Patients bonded with ceramic brackets experienced a higher and more severe pain of longer duration than individuals treated with conventional brackets.

Discomfort associated with Invisalign and traditional brackets: A randomized, prospective trial

OBJECTIVE

To evaluate differences in discomfort levels between patients treated with aligners and traditional fixed orthodontic appliances.

MATERIALS AND METHODS

This blinded, prospective, randomized equivalence two-arm parallel trial allocated 41 adult Class I nonextraction patients to either traditional fixed appliance (6 males and 12 females) or aligner (11 males and 12 females) treatment. Patients completed daily discomfort diaries following their initial treatment appointment, after 1 month and after 2 months. They recorded their levels of discomfort at rest, while chewing, and while biting, as well as their analgesic consumption and sleep disturbances.

RESULTS

Both treatment modalities demonstrated similar levels of initial discomfort. There were no significant sex differences. Patients in the traditional fixed appliances group reported significantly (P < .05) greater discomfort than patients in the aligner group during the first week of active treatment. There was significantly more discomfort while chewing than when at rest. Traditional patients also reported significantly more discomfort than aligner patients after the first and second monthly adjustment appointments. Discomfort after the subsequent adjustments was consistently lower than after the initial bonding or aligner delivery appointments. A higher percentage of patients in the fixed-appliance group reported taking analgesics during the first week for dental pain, but only the difference on day 2 was statistically significant.

CONCLUSIONS

Patients treated with traditional fixed appliances reported greater discomfort and consumed more analgesics than patients treated with aligners. This trial was not registered.

Non-pharmacological interventions for alleviating pain during orthodontic treatment

BACKGROUND

Pain is prevalent during orthodontics, particularly during the early stages of treatment. To ensure patient comfort and compliance during treatment, the prevention or management of pain is of major importance. While pharmacological means are the first line of treatment for alleviation of orthodontic pain, a range of non-pharmacological approaches have been proposed recently as viable alternatives.

OBJECTIVES

To assess the effects of non-pharmacological interventions to alleviate pain associated with orthodontic treatment.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 6 October 2016), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2016, Issue 9), MEDLINE Ovid (1946 to 6 October 2016), Embase Ovid (1980 to 6 October 2016) and EThOS (to 6 October 2016). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing a non-pharmacological orthodontic pain intervention to a placebo, no intervention or another non-pharmacological pain intervention were eligible for inclusion. We included any type of orthodontic treatment but excluded trials involving the use of pre-emptive analgesia or pain relief following orthognathic (jaw) surgery or dental extractions in combination with orthodontic treatment. We excluded split-mouth trials (in which each participant receives two or more treatments, each to a separate section of the mouth) and cross-over trials.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed risk of bias and extracted data. We used the random-effects model and expressed results as mean differences (MD) with 95% confidence intervals (CI). We investigated heterogeneity with reference to both clinical and methodological factors.

MAIN RESULTS

We included 14 RCTs that randomised 931 participants. Interventions assessed included: low-level laser therapy (LLLT) (4 studies); vibratory devices (5 studies); chewing adjuncts (3 studies); brain wave music or cognitive behavioural therapy (1 study) and post-treatment communication in the form of a text message (1 study). Twelve studies involved self-report assessment of pain on a continuous scale and two studies used questionnaires to assess the nature, intensity and location of pain.We combined data from two studies involving 118 participants, which provided low-quality evidence that LLLT reduced pain at 24 hours by 20.27 mm (95% CI -24.50 to -16.04, P < 0.001; I² = 0%). LLLT also appeared to reduce pain at six hours, three days and seven days.Results for the other comparisons assessed are inconclusive as the quality of the evidence was very low. Vibratory devices were assessed in five studies (272 participants), four of which were at high risk of bias and one unclear. Chewing adjuncts (chewing gum or a bite wafer) were evaluated in three studies (181 participants); two studies were at high risk of bias and one was unclear. Brain wave music and cognitive behavioural therapy were evaluated in one trial (36 participants) assessed at unclear risk of bias. Post-treatment text messaging (39 participants) was evaluated in one study assessed at high risk of bias.Adverse effects were not measured in any of the studies.

AUTHORS' CONCLUSIONS

Overall, the results are inconclusive. Although available evidence suggests laser irradiation may help reduce pain during orthodontic treatment in the short term, this evidence is of low quality and therefore we cannot rely on the findings. Evidence for other non-pharmacological interventions is either very low quality or entirely lacking. Further prospective research is required to address the lack of reliable evidence concerning the effectiveness of a range of non-pharmacological interventions to manage orthodontic pain. Future studies should use prolonged follow-up and should measure costs and possible harms.

Assessment of pain experience in adults and children after bracket bonding and initial archwire insertion

INTRODUCTION

Ninety five percent of orthodontic patients routinely report pain, due to alterations in the periodontal ligament and surrounding soft tissues, with intensity and prevalence varying according to age.

OBJECTIVE

This study aimed to assess toothache and buccal mucosal pain in adults and children during two initial phases of the orthodontic treatment.

METHODS

The intensity of toothache and buccal mucosal pain reported by 20 patients, 10 children (11-13 years) and 10 adults (18-37 years) was recorded with the aid of a Visual Analog Scale (VAS), during 14 days--7 days with bonded brackets only and 7 days with the initial archwire inserted.

RESULTS

There was no significant difference in pain intensity among adults and children. After bracket bonding, 50% of the children and 70% of the adults reported pain. 70% of both groups reported pain after initial archwire insertion. While adults reported constant, low intensity, buccal mucosal pain, the children showed great variation of pain intensity, but with a trend towards decreasing pain during the assessment period. After initial archwire insertion the peaks of toothache intensity and prevalence occurred 24 hours in children and 48 hours in adults.

CONCLUSIONS

In general, children reported pain less frequently than adults did, though with greater intensity.

Interventions for pain during fixed orthodontic appliance therapy. A systematic review

OBJECTIVE

To compare the different methods of pain control intervention during fixed orthodontic appliance therapy.

MATERIALS AND METHODS

A computerized literature search was performed in MEDLINE (1966-2009), The Cochrane Library (Issue 4, 2009), EMBASE (1984-2009), and CNKI (1994-2009) to collect randomized controlled trials (RCTs) for pain reduction during orthodontic treatment. Data were independently extracted by two reviewers and a quality assessment was carried out. The Cochrane Collaboration's RevMan5 software was used for data analysis. The Cochrane Oral Health Group's statistical guidelines were followed.

RESULTS

Twenty-six RCTs were identified and six trials including 388 subjects were included. Meta-analysis showed that ibuprofen had a pain control effect at 6 hours and at 24 hours after archwire placement compared with the placebo group. The standard mean difference was -0.47 and -0.48, respectively. There was no difference in pain control between ibuprofen, acetaminophen, and aspirin. Other analgesics such as tenoxicam and valdecoxib had relatively lower visual analog scale (VAS) scores in pain perception. Low-level laser therapy (LLLT) was also an effective approach for pain relief with VAS scores of 3.30 in the LLLT group and 7.25 in the control group.

CONCLUSIONS

Analgesics are still the main treatment modality to reduce orthodontic pain despite their side effects. Some long-acting nonsteroidal anti-inflammatory drugs (NSAIDs) and cyclo-oxygenase enzyme (COX-2) inhibitors are recommended for their comparatively lesser side effects. Their preemptive use is promising. Other approaches such as LLLT have aroused researchers' attention.

Effects of CO2 laser irradiation of the gingiva during tooth movement

Patients often feel pain or discomfort in response to orthodontic force. It was hypothesized that CO(2) laser irradiation may reduce the early responses to nociceptive stimuli during tooth movement. The distribution of Fos-immunoreactive (Fos-IR) neurons in the medullary dorsal horn of rats was evaluated. Two hrs after tooth movement, Fos-IR neurons in the ipsilateral part of the medullary dorsal horn increased significantly. CO(2) laser irradiation to the gingiva just after tooth movement caused a significant decrease of Fos-IR neurons. PGP 9.5- and CGRP-positive nerve fibers were observed in the PDL of all study groups. The maximum temperature below the mucosa during CO(2) laser irradiation was less than 40 degrees C. It was suggested that CO(2) laser irradiation reduced the early responses to nociceptive stimuli during tooth movement and might not have adverse effects on periodontal tissue.

Low-level laser therapy for pain caused by placement of the first orthodontic archwire: a randomized clinical trial

INTRODUCTION

The purpose of this study was to clinically evaluate the effect of low-level laser therapy (LLLT) as a method of reducing pain reported by patients after placement of their first orthodontic archwires.

METHODS

The sample comprised 60 orthodontic patients (ages, 12-18 years; mean, 15.9 years). All patients had fixed orthodontic appliances placed in 1 dental arch (maxillary or mandibular), received the first archwire, and were then randomly assigned to the experimental (laser), placebo, or control group. This was a double-blind study. LLLT was started in the experimental group immediately after placement of the first archwire. Each tooth received a dose of 2.5 J per square centimeter on each side (buccal and lingual). The placebo group had the laser probe positioned into the mouth at the same areas overlying the dental root and could hear a sound every 10 seconds. The control group had no laser intervention. All patients received a survey to be filled out at home describing their pain during the next 7 days.

RESULTS

The patients in the LLLT group had lower mean scores for oral pain and intensity of pain on the most painful day. Also, their pain ended sooner. LLLT did not affect the start of pain perception or alter the most painful day. There was no significant difference in pain symptomatology in the maxillary or mandibular arches in an evaluated parameter.

CONCLUSIONS

Based on these findings, we concluded that LLLT efficiently controls pain caused by the first archwire.

Pain relief by single low-level laser irradiation in orthodontic patients undergoing fixed appliance therapy

INTRODUCTION

The objective of this study was to analyze the effect of single low-level laser therapy (LLLT) irradiation on pain perception in patients having fixed appliance treatment.

METHODS

Seventy-six patients (46 women, 30 men; mean age, 23.1 years) enrolled in this single-blind study were assigned to 2 groups. The patients in group 1 (G1; 38 patients, 13 men, 25 women; mean age, 25.1 years) received a single course of LLLT (Mini Laser 2075, Helbo Photodynamic Systems GmbH & Co KG, Linz, Austria; wavelength 670 nm, power output 75 mW) for 30 seconds per banded tooth. The patients in group 2 (G2; 38 patients, 17 men, 21 women; mean age, 21.0 years) received placebo laser therapy without active laser irradiation. Pain perception was evaluated at 6, 30, and 54 hours after LLLT by self-rating with a standardized questionnaire.

RESULTS

Major differences in pain perception were found between the 2 groups. The number of patients reporting pain at 6 hours was significantly lower in G1 (n = 14) than in G2 (n = 29) (P <.05), and the differences persisted at 30 hours (G1, n = 22; G2, n = 33) (P <.05). At 54 hours, no significant differences were seen between the number of patients reporting pain (G1, n = 20; G2, n = 25), although the women had a different prevalence between G1 (n = 11) and G2 (n = 15) (P = .079). At 6, 30, and 54 hours, more than 90% of the subjects in both groups described the pain as "tearing."

CONCLUSIONS

LLLT immediately after multibanding reduced the prevalence of pain perception at 6 and 30 hours. LLLT might have positive effects in orthodontic patients not only immediately after multibanding, but also for preventing pain during treatment.

A longitudinal evaluation of pulpal pain during orthodontic tooth movement

OBJECTIVES

To examine the longitudinal changes in pulpal sensitivity to electrical stimulation and the relationship to pulpal sensitivity as measured by electrical stimulation and subjective reports of tooth pain after archwire insertion.

DESIGN

Non-randomized, prospective trial, with matched controls.

SETTING AND SAMPLE POPULATION

Regional Clinical Dental Research Center at the University of Washington School of Dentistry. Eighteen adult subjects of age 13-37 years. Nine experimental subjects planned for orthodontic treatment. Nine control subjects matched for gender and age who did not have orthodontic treatment.

EXPERIMENTAL VARIABLE

Fixed orthodontic appliances and initial archwire placement in experimental subjects compared with 'no treatment' control subjects.

OUTCOME MEASURE

Subjective assessments of orthodontic tooth pain were made using visual analogue scales. Electrically evoked detection and pain thresholds were determined using a computer-controlled tooth stimulator. Data were gathered at five time points: after bracket placement (baseline), 1 h after placement of initial archwires, 1 day after archwire placement, 1 week after archwire placement, and 1 month after archwire placement. Comparable time intervals were used for the 'no treatment' control subjects.

RESULTS

Subjective ratings of treatment-evoked tooth pain in the experimental group were the greatest at the post-archwire day 1 observation and progressively decreased for the remaining observations. Control subjects reported little pain at any of these observation times. The detection and pain threshold changes from baseline showed no statistical differences over time or between groups. While not statistically significant, a trend was noted where reports of greater orthodontic tooth pain were associated with increased sensitivity to electrical stimulation (i.e. lower detection and pain thresholds).

CONCLUSION

Orthodontic patients experience significant pain and discomfort 1 day after initial archwire placement (i.e. activation). Future research should investigate whether self-reports of treatment-evoked tooth pain intensity are associated with pulpal sensitivity.

Temporal and spatial distribution of Fos protein in the parabrachial nucleus neurons during experimental tooth movement of the rat molar

The present study was undertaken to reveal spatio-temporal changes in the distribution of Fos-like immunoreactive (-IR) neurons in the parabrachial nucleus (PBN), one of the important relay nuclei for processing autonomic and somatosensory information from the oro-facial regions, following the induction of experimental tooth movement in rat upper molars. The experimental tooth movement was induced by the insertion of elastic rubber between the first and second upper molars. In normal animals, the PBN contained a smaller number of Fos-IR neurons. Following experimental tooth movement, the Fos-IR neurons increased in number significantly on both the ipsilateral and contralateral PBN, reaching a maximum at 4 h (about 10 times that of normal animals), and then decreased gradually. However, a significant number of Fos-IR neurons remained at 24 h post-operation. Remarkable side-by-side differences in the number of Fos-IR neurons were recognized at 1 to 4 h following the experimental tooth movement. Their number returned to normal (basal) levels at 5 days post. All subnuclei of PBN showed similar temporal changes in the number of Fos-IR neurons, this being particularly apparent in lateral PBN. Administrations of morphine (3 and 10 mg/kg, i.p.) drastically reduced the induction of Fos-IR neurons in all subnuclei of both the ipsilateral and contralateral PBN in a dose-dependent manner, and its effect was antagonized by pretreatment with naloxone (2 mg/kg, i.p.). The reduction of Fos-IR neurons by morphine pretreatment suggests that the appearance of Fos-IR neurons in the PBN may be partly due to the noxious stimulation and/or stress arising from tooth movement. The bilateral expression of Fos-IR neurons in the PBN indicates that the experimental tooth movement causes the activation of PBN neurons for the processing of somatosensory as well as autonomic information. The prolonged expression of Fos-IR neurons in all the subnuclei of bilateral PBN reflects clinical features of the transient discomfort and/or abnormal sensations, which many patients often complain about during orthodontic treatment.

Effects of morphine on the distribution of Fos protein in the trigeminal subnucleus caudalis neurons during experimental tooth movement of the rat molar

The present study was undertaken to disclose temporal changes in the distribution of Fos-like immunoreactive (-IR) neurons in the trigeminal subnucleus caudalis (SpVc), one of the important relay nuclei for processing the nociceptive information from the oro-facial regions, following induction of experimental tooth movement in rat upper molars. Furthermore, the effect of morphine and naloxone on the levels of Fos-IR neurons in the SpVc was examined. The experimental tooth movement was induced by insertion of an elastic rubber between the first and second upper molars. In normal animals, Fos-IR neurons were rarely observed in the SpVc. Immediately after insertion of the elastic band, the distribution of Fos-IR neurons was comparable to that observed in normal animals. The number of Fos-IR neurons increased significantly from 1 to 4 h following the induction of experimental tooth movement, reaching a maximum at 2 h, and then decreasing gradually. Most of the neurons were localized in the dorsomedial portion of the superficial layers of the ipsilateral SpVc near the obex, but a few were observed at the ventral portion of the SpVc. The neurons at the superficial layers and ventral portion of the contralateral SpVc also showed Fos-like immunoreactivity, but their numbers were significantly smaller than those on the ipsilateral side. Pretreatment with morphine (3 and 10 mg/kg, i.p.) significantly reduced the induction of Fos-IR neurons at the superficial layers of the ipsilateral SpVc in a dose-dependent manner, and its effect was antagonized by the subsequent treatment of naloxone (2 mg/kg, i.p.). Naloxone pretreatment enhanced the expression of Fos-IR neurons on the ipsilateral SpVc. The present results of a reduction of Fos-IR neurons by morphine pretreatment suggest that the induction of Fos-IR neurons may be due to the noxious stimulation caused by induction of experimental tooth movement.

A clinical investigation of the efficacy of low level laser therapy in reducing orthodontic postadjustment pain

Low level laser therapy (LLLT) has been shown to produce analgesic effects in many clinical applications. The aim of this clinical study was to test the efficacy of LLLT in controlling orthodontic postadjustment pain. Thirty-nine volunteers were selected for this study that used a double-blind design with placebo control. Elastomeric separators were placed at the proximal contacts of one premolar in each quadrant of the dentition to induce orthodontic pain. The tip of a 30 mW gallium-arsenide-aluminium (830 nm) diode laser probe was then placed at the buccal gingiva and directed at the middle third of the root. Three different treatment durations of 15, 30, and 60 seconds and one placebo treatment of 30 seconds were tested within each subject. The study was conducted over 5 days, and the visual analogue scale (VAS) was used to quantify the pain experienced by the subjects before and after laser applications for each day. Analysis of the VAS median scores showed that teeth exposed to laser treatment had lower levels of pain as compared with those with the placebo treatment. However, nonparametric statistical analysis of the data showed that the differences between treatments and placebo within each subject were not statistically significant.

Role of periodontal ligament receptors in the tactile function of teeth: a review

The tactile function of the human periodontal mechanoreceptors has mostly been studied by psychophysical approaches. It was concluded that periodontal mechanoreceptors play a major role in the tactile function of teeth. It must be noted however that the interocclusal tactile threshold is not solely determined by periodontal mechanoreceptors but also by pulpal, muscular or articular receptors. While temporomandibular joint receptors play a minor role, muscular receptors are important in the discriminatory ability for a mouth opening of 5 mm and more. To discriminate between the contribution of periodontal and other receptors in the oral tactile function, future studies should use appropriate psychophysical methodologies and well-defined stimulus parameters.

Patient discomfort levels at the time of debonding: a pilot study

Several investigations have evaluated the degree of discomfort that patients experience during orthodontic treatment, but most of the research centered on tactile sensory (touch) threshold, reaction to spacers used to separate the teeth or reaction to the initial leveling wires, and the periodic adjustment of the appliances. The purpose of this investigation is to determine the discomfort threshold for patients undergoing orthodontic treatment at the time immediately before appliance removal. Such information will be useful in determining the force levels that patients can tolerate during debonding. From the findings in this study the following can be concluded: (1) The threshold of patient discomfort, at the time of debonding, is significantly influenced by two factors: the mobility of the tooth and the direction of force application. Sex and tooth type differences also influence the discomfort threshold but to a lesser degree. (2) At the time of debonding, patients can withstand intrusive forces significantly more than forces applied in a mesial, distal, facial, lingual, or an extrusive direction. The clinical implications of these findings are discussed.

Perception of discomfort by patients undergoing orthodontic treatment

The purpose of this study was to determine the perception of discomfort over time by a group of 70 patients undergoing orthodontic treatment. Patients who were selected for comprehensive orthodontic treatment completed questionnaires before insertion of separators and initial arch wires and after placement at 4 hours, 24 hours, and 7 days. The level of discomfort during these time periods was assessed by a visual analogue scale. The results showed a significant increase in the level of discomfort after insertion of either separators or arch wires at 4 hours and 24 hours, but not at 7 days. No significant difference was found in the level of discomfort of patients more than 16 years of age compared with those 16 years and under. No significant difference in discomfort was found between the sexes. These results are useful in relating expectations of discomfort to patients who undergo orthodontic treatment.

Traumatic ulcers and pain in adults during orthodontic treatment

In the present investigation the frequency of oral ulcers and pain in 79 adults orthodontic patients was recorded. Only four of all patients had never had oral ulceration during treatment, but 83% of the patients characterized the trouble as minor. About 47% of the patients said that ulcers caused by the fixed appliance were the most annoying part of the treatment, and 38% said that activation of the appliance caused the most discomfort. In about 63% of the patients there was less pain when the treatment had lasted for some months, and in 24% there was no significant change in the discomfort. The pain following activation lasted for only 2-3 days (71%), but 20% had pain for more than 3 days, and five individuals felt pain constantly. The recurrence of aphthous ulceration (RAU) was not significantly affected during the orthodontic treatment, and in only one case was there an increase in the occurrence of herpes labialis.

Initial tooth movement: force application and pain--a relationship?

Initial dental casts of 24 patients, who had previously completed a discomfort index card for the first 16 days following placement of a fixed appliance, were examined. A method is described whereby the anterior and overall crowding in the relevant dental arch was measured as a tooth/arch discrepancy index using the reflex metrograph. The crowding was measured in three dimensions as the discrepancy between the sum of the anatomic mesiodistal widths of the teeth and the actual mean arch shape canine to canine (3 to 3) and first molar to first molar (6 to 6) inclusive. An additional two-dimensional method using the best "goodness of fit" (least variance) of a parabolic arch shape for the mean arch length in the 6 to 6 crowding measurement is also described. The measurement accuracy of the reflex plotter was less than 0.12 mm. The method error for the crowding measurements expressed as root mean square (RMS) values was 0.97 mm for the anterior tooth/arch, 1.45 mm for the overall tooth/arch discrepancies, and 1.35 mm for the tooth/arch discrepancy based on the best fit of a parabolic curve. It is proposed that since the same bracket width and fully engaged arch wire type were used in every case, some relationship between the initial crowding that reflected the forces applied and the discomfort experienced by the patients might be expected. This was not found to be true. There was no correlation between the total discomfort experienced and the crowding measurements 3 to 3 or 6 to 6.(ABSTRACT TRUNCATED AT 250 WORDS)