The effectiveness of interventions in reducing pain related to orthodontic separation: a systematic review and meta-analysis.

Background: Pain is an unpleasant experience and annoying sensation. To control this pain during orthodontic separation, different pharmacological and non-pharmacological methods have been used.

Objective: This systematic review and meta-analysis aimed to critically assess the evidence of the effectiveness of pharmacological and non-pharmacological methods in reducing pain induced by orthodontic separation.

Search strategy: An electronic search was conducted using the following databases: PubMed® (Medline), Scopus®, EMBASE®, Web of ScienceTM, Google ScholarTM, ProQuest, and Cochrane Central Register of controlled trials (CENTRAL) searching for the studies published between January 2012 and April 2023.

Selection criteria: Only randomized controlled trials (RCTs) were included, each experimental group included patients who received elastomeric separators and one kind of pharmacological or non-pharmacological interventions for pain reduction during the separation stage.

Data collection and analysis: Cochrane's risk of bias tool (RoB2 tool) was applied. The Grading of Recommendations Assessment, Development, and Evaluation [GRADE] approach was used to evaluate the strength of the evidence.

Results: Thirty-one studies (RCTs) were included in this systematic review. Nineteen of them were appropriate for quantitative synthesis and used VAS for pain assessment. Meta-analysis showed that low-level laser therapy (LLLT) was an effective approach for pain relief after separators placement with standard mean difference of 13.79 mm (95% confidence interval (CI): -15.64, -11.94) at 6 h and 23.34 mm at 24 h (95% CI: -25.91, -20.77). LLLT was also effective when applied in split-mouth and the standard mean difference was 8.9 mm at 6 h (95% CI: -12.86, -3.33) and 17.15 mm at 24 h (95% CI: -30.12, -4.17). Ibuprofen had a pain control effect at 6 h and at 24 h compared with the placebo group. The standard mean difference was 14.37 mm (95% CI: -20.54, -8.19) and 20.46 mm (95% CI: -27.79, -13.13), respectively. There was no difference in pain control between ibuprofen and acetaminophen. Naproxen had lower visual analog scale scores in pain perception at 6 h and the standard mean difference was 7.03 mm (95% CI: -12.67, -1.40).

Conclusions: The application of LLLT decreased the pain induced by the separation during the first day of teeth separation; the pain reduction showed an increase from 6 h to the end of the 24 h. However, the evidence is weak to moderate. The analgesics reduced the pain compared to placebo; this pain reduction had shown an increase from 6 h to the end of the 24 h. The strength of the evidence is moderate. Naproxen gel effectively reduced the pain compared to placebo; the evidence in this regard is moderate. Naproxen gel effectively reduced the pain compared to placebo, but it was less effective than the oral intake of non-steroidal anti-inflammatory drugs. However, the evidence in this regard is moderate.

Registration: This systematic review was registered with PROSPERO (CRD42022335553) during the first stages of its conduction.