Evaluation of rapid maxillary expansion through acoustic emission technique and relative soft tissue attenuation.
Acoustic emission (AE) is a non-destructive test to detect energy release. This technique was applied during rapid maxillary expansion (RME) to evaluate the reaction of the craniofacial skeleton.



A swine model was analysed. Soft tissues were removed from two heads, while other two were preserved intact. A palatal expander (PE) was positioned and AE sensors were placed on the intermaxillary, fronto-nasal, and maxillo-lacrimal sutures. The PE was activated and AE recorded during RME. Differences between parameters were analysed with Mann-Whitney U test and Kruskal-Wallis test, and correlations with Spearman-Rho test (significance p<0.05).



PE activations were accompanied by clusters of AE hits. In the presence of soft tissues, amplitudes were generally lower (p<0.001) and durations were higher (p<0.001). No differences were found in the respective energy values. Differences were found in the AE (p<0.05) among the four channels, with AE characterised by higher values in proximity of the maxillo-lacrimal sutures. High-energy hits were represented by burst-type waves, and low-energy ones by continuous-type.



Although soft tissues create possible attenuation of the signal, AE can be detected during RME with sensors on the skin. AE provided further information of energy release, on top of the mechanical parameters. Source location was one of the main limitations.
Dental Materials Science, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, PR China; Department of Orthodontics, Dental School, University of Brescia, Brescia, Italy.
Fabio
F
Savoldi
Dental Materials Science, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, PR China. Electronic address: jkhtsoi@hku.hk.
James K H
JKH
Tsoi
Department of Orthodontics, Dental School, University of Brescia, Brescia, Italy.
Corrado
C
Paganelli
Dental Materials Science, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, PR China.
Jukka P
JP
Matinlinna
D000162:Acoustics; D000818:Animals; D001696:Biomechanical Phenomena; D008437:Maxilla / Q000502:physiology*; D010155:Palatal Expansion Technique; D010159:Palate / Q000502:physiology*; D013552:Swine
Acoustic emission; Biomechanics; Craniofacial; Rapid maxillary expansion; Sutures