A randomised controlled crossover trial comparing two mandibular repositioning appliances for treatment of moderate obstructive sleep apnoea
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Published on: December 6, 2016
Jorden Blok1, Zoë Van Houtvinck2, Susie Klerkx3
1Oral and Maxillofacial Surgery department, Ziekenhuis Oost-Limburg (ZOL), Genk, 3600, Belgium. jordenblok@hotmail.com.
Purpose:
To compare two custom-made bi-block mandibular repositioning appliances, the SomnoDent® Flex and the OrthoApnea NOA®, in adults with moderate obstructive sleep apnoea (OSA).
Methods:
Randomised two-period, two-sequence crossover trial at a single centre (Genk, Belgium). Adults with polysomnography-confirmed AHI 5-30 events/h were eligible; all enrolled had moderate OSA (AHI 15.1-29.7). Participants were randomised 1:1 to SomnoDent® Flex-NOA® or the reverse sequence, each worn for three months with a two-week washout. Participants and clinicians were unblinded; outcome scorers were blinded to appliance. The registered primary outcome was the change in AHI from baseline for each appliance. The between-appliance difference in post-treatment AHI was assessed in a non-prespecified principal comparative analysis using linear mixed-effects models with appliance, period and sequence as fixed effects.
Results:
Sixteen participants were randomised, eight per sequence, and all were analysed. Median AHI fell from 17.6 events/h at baseline to 3.1 with the SomnoDent® Flex and 2.3 with the NOA® (both p < 0.001 versus baseline). The between-appliance difference was + 0.16 events/h (95% CI - 2.56 to + 2.87; p = 0.904), with a period effect (+ 3.82 events/h in period 2, coinciding with the change from home polygraphy to in-laboratory polysomnography; p = 0.009). No secondary outcome differed significantly; post hoc, AHI < 5 events/h was reached in 12/16 (SomnoDent® Flex) and 10/16 (NOA®). No participant discontinued for an adverse event; adverse events were not systematically recorded.
Conclusion:
Both appliances were associated with reductions in AHI. The non-prespecified between-appliance comparison detected no statistically significant difference and does not establish equivalence. Complete confounding between period and measurement methodology, together with insufficient adherence, titration and adverse-event data, limits conclusions about the overall comparative merits of the appliances.
Trial Registration:
ClinicalTrials.gov NCT06810479, registered 5 February 2025, prior to first enrolment.
