Does adding a mandibular mentoplate improve long-term Class III treatment?

Abstract

A commentary on: Meyns J, Meewis J, Dons F, Schreurs A, Aerts J, Shujaat S, Politis C, Jacobs R. Long-term comparison of maxillary protraction with hybrid hyrax-facemask vs. hybrid hyrax-mentoplate protocols using Alt-RAMEC: a 5-year randomised controlled trial. Eur J Orthod. 2025;47(2):cjaf011. https://doi.org/10.1093/ejo/cjaf011 .

Design: Single-centre two-arm parallel randomised controlled trial with 1:1 allocation and 5-year follow-up.

Case selection: Twenty-eight children in the mixed dentition with skeletal Class III malocclusion were recruited. Eligible patients had an anterior crossbite or edge-to-edge incisor relationship and a Class III molar relationship. Children with craniofacial syndromes, previous orthodontic or surgical treatment, marked skeletal asymmetry or functional Class III malocclusion were excluded. Participants were allocated to hybrid Hyrax plus facemask therapy or hybrid Hyrax plus mandibular mentoplate therapy. Both groups received Alt-RAMEC.

Data analysis: Low-dose computed tomography was performed at baseline, 1 year and 5 years. Virtual lateral cephalograms were used to assess Wits appraisal as the primary outcome with skeletal and dentoalveolar variables as secondary outcomes. Between-group comparisons used unpaired two-sided t tests. Outcome assessment and statistical analysis were blinded. Measurement reliability was assessed using intraclass correlation coefficients.

Results: Twenty-four of 28 randomised participants contributed data at 5 years. Wits appraisal improved by 4.42 mm with facemask treatment and 2.86 mm with mentoplate treatment at 1 year. At 5 years the corresponding improvements from baseline were 3.33 mm and 1.50 mm. Between-group differences were not statistically significant. Long-term vertical skeletal measures and incisor inclination were also comparable. Minor hook fracture and mucosal irritation occurred without treatment discontinuation.

Conclusions: Adding a mandibular mentoplate did not demonstrate superior long-term skeletal correction over hybrid Hyrax plus facemask treatment in this small trial. The findings support selective rather than routine use of the more invasive approach. They do not establish equivalence between the protocols.