# Changes in vertical skeletal and neuromuscular balance in growing patients treated with AMCOP®: a cephalometric and EMG evaluation

## TL;DR

This study evaluates how AMCOP® appliances affect jaw growth and muscle balance in children, showing positive changes in bite and muscle activity.

## Contribution

The study introduces a novel evaluation of AMCOP® appliances using both cephalometric and sEMG data in growing patients.

## Key findings

- AMCOP® treatment reduced anterior open bite and controlled vertical divergence effectively.
- sEMG showed improved neuromuscular balance with normalized barycenter and increased efficiency.
- Upper incisors uprighted while lower incisors remained stable during treatment.

## Abstract

To evaluate changes in vertical skeletal dimensions and neuromuscular balance in growing patients treated with AMCOP® elastodontic appliances, by comparing pre- and post-treatment cephalometric values (Deltadent®) and standardized surface EMG indices.

This monocentric retrospective case series included 9 consecutive children in deciduous/early mixed dentition treated with AMCOP® according to a staged protocol (Open phase for vertical control, then class-specific device when indicated). Wear was prescribed 1 h/day plus nocturnal use. Lateral cephalograms were traced in Deltadent® at baseline (T0) and after therapy (T1). Primary outcomes were overbite and vertical divergence (SN-GoGn; PP-MP). Secondary outcomes included ANS-Me, overjet, interincisal angle, U1-PP and L1-MP. Neuromuscular balance was assessed with Teethan® (POC TA/MM, BAR, TORS, IMP, ASIM), recorded per SENIAM recommendations. Reliability was checked with ICC and Dahlberg's error; paired comparisons used standard parametric/non-parametric tests (α = 0.05).

Treatment was completed without adverse events (median duration ≈12–16 months). Most patients showed closure or reduction of anterior open bite, decreased or well-controlled vertical divergence, increased interincisal angle, and reduced overjet, with upper incisor uprighting and stable lower incisor inclination. sEMG demonstrated consistent improvement: barycenter (BAR) shifted toward the normative zone, torsion/asymmetry indices decreased, and global efficiency (IMP) increased.

In growing patients, AMCOP® therapy was associated with favorable vertical control and measurable neuromuscular rebalancing, documented by objective cephalometric and EMG metrics. Prospective controlled studies are warranted to confirm efficacy and long-term stability.