# Glass ionomer open exposure and closed exposure of palatally displaced canines: a randomised controlled trail comparing postoperative pain perception and complications

**Authors:** Anna Dahlén, Viktoria Tagesson, Damon Taheri, Ken Hansen, Larisa Krekmanova, Julia Naoumova

PMC · DOI: 10.1093/ejo/cjag011 · The European Journal of Orthodontics · 2026-03-17

## TL;DR

A study compares two surgical techniques for treating palatally displaced canines, finding no major differences in long-term pain or complications.

## Contribution

This randomized controlled trial provides evidence comparing glass ionomer open exposure and closed exposure techniques for palatally displaced canines.

## Key findings

- GOPEX patients reported higher pain during the first postoperative week.
- Overall pain scores and analgesic use across the full recovery period were similar between groups.
- Surgery duration and complication rates were comparable for both techniques.

## Abstract

The most common surgical interventions for palatally displaced canines (PDCs) are open and closed exposure, yet there is no consensus on which exposure technique is preferable.

To compare glass ionomer open exposure (GOPEX) with closed exposure (CE) in terms of patient-reported outcomes, surgical duration, and complications.

The trial design was a single centre, randomised controlled trial, with a 1:1 allocation of two parallel groups.

Patients aged ≤18 years, with a unilateral PDC in sector 2–5, requiring surgical exposure were randomly allocated to GOPEX or CE. Patient-reported outcomes were collected through a questionnaire completed over the phone daily from the day of exposure until symptom resolution. Surgery duration, recorded by the operator, and complications within four weeks, was obtained from the patient’s record. The outcome assessor and the individual conducting the follow-up calls were blinded to group allocation. Repeated measures analyses were used for data collected at multiple time points. Mann–Whitney U-test, chi-square test or Fisher’s exact test, as appropriate was used for other between-group comparisons.

Of the 92 patients randomised, 83 completed the intervention: 43 in the GOPEX group (13.8 ± 1.5 years) and 40 in the CE group (13.6 ± 1.2 years). Throughout the full postoperative period, the groups did not differ significantly in pain levels, percentage of pain-free patients, analgesic use, or chewing difficulty. During the first postoperative week, however, the GOPEX group reported higher pain (fold change 1.78; 95% CI: 1.07–2.99; P = 0.028). Fewer GOPEX patients were pain-free at one week, and they consumed more analgesics on postoperative days 4 and 5. Surgery duration was similar between groups, and complications were rare and comparable.

Although the GOPEX group reported more pain during the first postoperative week, overall pain scores and analgesic consumption across the full postoperative period did not differ between groups. No significant differences were found in surgery duration or complications.

www.researchweb.org/is/sverige, registration number: 279469.

## Full-text entities

- **Genes:** PDC (phosducin) [NCBI Gene 5132] {aka MEKA, PHD, PhLOP, PhLP}
- **Diseases:** school absence (MESH:D010698), root resorption (MESH:D012391), Functional jaw impairment (MESH:D007571), postoperative infection (MESH:D013530), Infection (MESH:D007239), Bleeding (MESH:D006470), Craniofacial syndromes (MESH:C565118), impaction (MESH:D004834), DC (MESH:D054221), PDC (MESH:C537181), cleft lip and/or palate (MESH:D002971), Pain (MESH:D010146), postoperative pain (MESH:D010149), gingival overgrowth (MESH:D019214), swelling (MESH:D004487), eruption (MESH:D003875), GOPEX (MESH:C567350), PDCs (MESH:D004283), chewing difficulty (MESH:D051346), fever (MESH:D005334), Dental fear (MESH:C000719212), Complications (MESH:D008107), displaced (MESH:D006617)
- **Chemicals:** Paracetamol (MESH:D000082), CE (-), Lidocaine (MESH:D008012), Glass ionomer (MESH:C015897), ibuprofen (MESH:D007052), Adrenalin (MESH:D004837), midazolam (MESH:D008874), phosphoric acid (MESH:C030242), Cyklokapron (MESH:D014148), nitrous oxide (MESH:D009609), Diazepam (MESH:D003975)
- **Species:** Homo sapiens (human, species) [taxon 9606], Canis lupus familiaris (dog, subspecies) [taxon 9615], Pseudomonas sp. DC (species) [taxon 91503]

## Full text

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## Figures

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## References

34 references — full list in the complete paper: https://tomesphere.com/paper/PMC13016904/full.md

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Source: https://tomesphere.com/paper/PMC13016904