University of Oulu

Johanna Julku, Matti Hannula, Kirsi Pirilä-Parkkinen, Mimmi Tolvanen, Pertti Pirttiniemi, Dental arch effects after early and later timed cervical headgear treatment—a randomized controlled trial, European Journal of Orthodontics, Volume 41, Issue 6, December 2019, Pages 622–630,

Dental arch effects after early and later timed cervical headgear treatment—a randomized controlled trial

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Author: Julku, Johanna1,2,3; Hannula, Matti2,3; Pirilä-Parkkinen, Kirsi1,3;
Organizations: 1Oral and Maxillofacial Department, Oulu University Hospital
2Department of Oral Development and Orthodontics, Research Unit of Oral Health Sciences, University of Oulu, Finland
3MRC Oulu, Oulu University Hospital and University of Oulu, Finland
4Department of Community Dentistry, Institute of Dentistry, University of Turku, Finland
5Center for Life Course Health Research, Faculty of Medicine, University of Oulu, Finland
Format: article
Version: accepted version
Access: open
Online Access: PDF Full Text (PDF, 0.5 MB)
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Language: English
Published: Oxford University Press, 2019
Publish Date: 2020-04-08


Background: Cervical headgear (CH) is a commonly used orthodontic appliance and its dentoalveolar changes are known. However, the effects related to gender and timing have gained less attention.

Objectives: To examine dimensions of dental arches among children with Class II occlusion without posterior mandibular rotation according to timing of Kloehn-type CH treatment.

Trial design: Prospective, randomized, parallel-group controlled trial.

Methods: Sixty-seven seven-year-old children with a Class II occlusion were included in the study. The children were randomized into two equal-size groups in 1:1 ratio by sealed-envelope randomization. The early group (EG, n = 33) was treated between T₀ and T₁ (26 months), right after eruption of the first maxillary molars. The late group (LG, n = 34) was treated between T₁ and T₂ (24 months). The children were treated with CH until normal Class I occlusion on first molars was achieved. Impressions for dental casts were taken from all participants at T₀, T₁, and T₂. Blinding was applicable for outcome assessors. Changes in dental cast measurements were compared between the groups and genders using t-test, Mann-Whitney U-test, and repeated measures analysis of variance.

Results: Of the children, 56 completed the study. The maxillary arch length and the transversal changes between the upper canines and upper first molars were significantly increased in EG at T₀−T₁ (P < 0.001). At T₂, the transversal dimension between the upper first molars was larger (P < 0.05), and in the lower arch the mandibular arch length (P < 0.05) and the transversal dimension between the lower first molars (P < 0.01) were increased in EG males compared to LG males. No harms were encountered.

Conclusions: The male gender benefits most from early timing of the CH treatment, showing larger dimensions at the end of the follow-up. The results clearly indicated a wider and longer upper dental arch and spontaneous expansion of the lower dental arch after treatment.

Clinical registration: NCT02010346.

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Series: European journal of orthodontics
ISSN: 0141-5387
ISSN-E: 1460-2210
ISSN-L: 0141-5387
Volume: 41
Issue: 6
DOI: 10.1093/ejo/cjy083
Type of Publication: A1 Journal article – refereed
Field of Science: 313 Dentistry
Funding: The study was supported by the Finnish Dental Society Apollonia.
Copyright information: © The Author(s) 2019. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model ( This is a pre-copyedited, author-produced version of an article accepted for publication in European Journal of Orthodontics following peer review. The version of record is available online at: