Interleukin-1  levels, pain intensity, and tooth movement using two different magnitudes of continuous orthodontic force

Abstract

This study aimed to determine the optimum orthodontic force from a broader perspective. Interleukin (IL)-1β levels in human gingival crevicular fluid (GCF), pain intensity, and the amount of tooth movement were measured during canine retraction using different magnitudes of continuous orthodontic force. Sixteen subjects (two males and 14 females), aged 18-24 years, diagnosed with Class I bimaxillary protrusion and treated with first premolar extractions participated in this study. The upper canines were retracted with continuous forces of 50 or 150 g using nickel-titanium coil springs on segmented archwires. One of the lower canines was used as a control. GCF was collected from the distal site of each tooth at specific time points. IL-1β concentrations, pain intensity, using the visual analogue scale (VAS), and the amount of tooth movement were evaluated. One-way analysis of variance, Friedman, and paired t-tests were used for comparisons of IL-1β in GCF, the plaque and gingival indices, and the efficiency of tooth movement on pain perception, respectively. IL-1β concentration in the 150 g group showed the highest level at 24 hours and 2 months with significant differences compared with the control group (P < 0.05). The mean VAS score of pain intensity from the 150 g force was significantly greater than from the 50 g force at 24 hours (P < 0.01). However, no significant difference in the amount of tooth movement was found between these two different magnitudes of continuous force at 2 months. A 50 g force could effectively induce tooth movement similar to 150 g with less pain and less inflammation.

Orthodontic pain trajectories in adolescents: Between-subject and within-subject variability in pain perception

“…4 Generally it is claimed that peak orthodontic pain level is reached on day one morning or 24 hours after orthodontic separator placement. 1,2,5,6 However, this claim made by authors of previous studies has an inherent flaw, as rightly pointed out by the authors of a recent study. 7 Since none of the previous studies reported the actual time of force application and the subsequent time of pain assessment, therefore, it is difficult to ascertain the actual time of peak intensity level.…”

“…2,5,6 However, unlike these previous studies which made generalized claims regarding these effects, we were able to explicitly explore the simultaneous effect of age and sex of individual on all three areas of interest i.e. mean average trajectories, BS variation, and WS variation.…”

“…These substances, which are essential for bone remodelling during tooth movement, also result in pain. 1,2 Pain is both patient and time dependent resulting in substantial heterogeneity in patients' reported pain trajectories over time. 3 Put differently, pain is both a between-subject (BS) and within-subject (WS) phenomenon.…”

Pain experience during initial alignment with three types of nickel-titanium archwires: A prospective clinical trial

“…4,21 On the other hand, a recent study concluded that heavy forces produce significantly greater pain than light forces 24 hours after force application. 22 The introduction of nickel-titanium archwires has revolutionized the field of orthodontics because of the ability of these archwires to deliver light continuous forces, thus increasing the intervals between appointments. * Two patients reported no pain at all.…”

“…An increased concentration of interleukin-1b (inflammatory mediator that induces the secretion of pain-producing substances) in human gingival crevicular fluid was found after 1 hour of orthodontic force application that reaches its peak level after 24 hours and subsequently declines to normal level in 1 week to 1 month. 22 As a second form of pain intensity assessment, patients were asked to report the use of self-prescribed analgesics. A high percentage (67%) of patients relied on analgesics for symptomatic relief in the week following orthodontic appliance placement, which underlines the severity of orthodontic pain.…”