Biomechanical behaviour of craniofacial sutures during distraction: An evaluation all over the entire craniofacial skeleton

Objective. Sutures are fibrous joints connecting the bones of the head. Despite the funda-mental role played by sutures in dentofacial orthopaedics, their biomechanical propertiesare not completely understood. This study evaluated anatomy, biomechanics, and acousticemission (AE) during distraction of the sutural ligament (SL).Methods. Seventy-two suture samples were removed from a twelve-months-old swine (Susscrofa) head. Each volume was acquired using micro-computed tomography (CT), and thelinear interdigitation index was calculated on both planes (LIICORand LIISAG). Mechanicaltesting till failure was carried at 1 mm/min, and four piezoelectric sensors were used forrecording of amplitude (A), duration (D), and energy (E) of AE. The relationships betweeninterdigitation, fracture types, tensile stress (0), and AE were statistically analysed withnon-parametric tests ( ̨ = 0.05).Results. 0of the SL had median values of 4.0 MPa, and AE were characterised by A of 49.3 dB(IQR = 2.2), D of 826.3 s (IQR = 533.4), and E of 57,715.8 eu (IQR = 439,613.5). Most of the frac-tures happened in the SL (46%), some within the bone (34%), and fewer were combined (19%).LIICORhad correlation with A (0.383, p = 0.028), D (0.348, p = 0.048), and E (0.437, p = 0.011) ofthe AE, and 0had similar relationship with A (0.500, p = 0.003), D (0.495, p = 0.003), and E(0.579, p < 0.001). Maximum energy values were different between fractures within the boneand within the SL (p = 0.021).Significance. Biomechanical properties under tension of most of the sutures of the craniofacialskeleton were reported. AE provided information about the sequence of events during SLdistraction, and had significant relationship with its mechanical properties. Further studiesare necessary to confirm these preliminary findings, and to identify their relationship withbiological processes and dentofacial treatments