Evaluation of Pain Perception and Analgesic Requirement during Initial Alignment Phase in Fixed Orthodontic Treatment

Abstract

Background: Pain following placement of the initial aligning archwire is one of the most common and clinically significant adverse effects of fixed orthodontic treatment, driven by an inflammatory response within the periodontal ligament. Despite its high prevalence, the full pain trajectory and its relationship with analgesic use and patient-related factors such as dental anxiety remain incompletely characterized in prospective, longitudinal cohorts.

Objectives: To characterize pain perception and analgesic consumption during initial alignment of fixed orthodontic treatment and identify predictors of a high pain and analgesic burden.

Methods: In this prospective, longitudinal, observational cohort study, 100 consecutive patients (58% female; mean age 21.5 ± 5.2 years) beginning fixed orthodontic treatment with an initial NiTi or Cu-NiTi archwire (0.012–0.016 inch) completed a pain diary recording visual analogue scale (VAS) scores at nine time points over 14 days and analgesic intake during week 1. Dental anxiety was assessed at baseline using the Modified Dental Anxiety Scale. Associations of pain burden, peak pain, and analgesic consumption with age, gender, archwire characteristics, anxiety, and prior orthodontic experience were tested using Mann-Whitney U, Kruskal-Wallis H, Spearman correlation, and multivariable regression.

Results: Pain rose sharply after placement, peaked between 24 hours and Day 2 (mean VAS 51.9 mm), and resolved by Day 14 (mean 8.3 mm; Friedman χ² = 546.95, p < 0.001). Ninety-seven percent of patients used at least one analgesic (median 5 tablets), predominantly ibuprofen (55.7%). Dental anxiety was the only independent predictor of pain burden (B = 14.95, p < 0.001) and high analgesic use (OR = 1.13, p = 0.044); age, gender, archwire material/size, and prior experience showed no independent association.

Conclusions: Pain after initial archwire placement follows a predictable trajectory, peaking within 72 hours and resolving by two weeks. Dental anxiety, rather than demographic or appliance-related factors, is the dominant predictor of pain and analgesic burden, supporting routine anxiety screening in pre-treatment orthodontic counselling.