Effect of Piezoelectric Sutural Ostectomies on Accelerated Bone-Borne Sutural Expansion

Abstract

The present study investigated the effect of piezoelectric sutural ostectomies on accelerated bone-borne sutural expansion. Sixteen male New Zealand white rabbits (20 to 24weeks old) were randomly divided into 4 experimental groups (n=4): group 1, conventional rapid sutural expansion; group 2, accelerated sutural expansion; group 3, accelerated sutural expansion with continuous ostectomy; and group 4, accelerated sutural expansion with discontinuous ostectomy. All sutural ostectomies were performed using a piezoelectric instrument (Woodpecker DTE, DS-II, Guangxi, China) before expander application with the rabbits under anesthesia. Modified hyrax expanders were placed across the midsagittal sutures of the rabbits and secured with miniscrew implants located bilaterally in the frontal bone. The hyrax expanders were activated 0.5mm/day for 12days (group 1) or with a 2.5-mm initial expansion, followed by 0.5mm/day for 7days (groups 2 to 4). After 6weeks of retention, the bone volume fraction, sutural separation, and new bone formation were evaluated using micro-computed tomography and histomorphometry. Statistical analysis was performed using Kruskal-Wallis and Mann-Whitney U tests and Spearman's rho correlation (P<.05). Ranking of the median sutural separation was as follows: group 1, 3.05mm; group 2, 3.97mm; group 4, 4.78mm; and group 3, 5.66mm. The least and most bone formation were observed in groups 1 (63.63%) and 3 (75.93%), respectively. Spearman's correlation showed a strong, positive, and significant correlation (r=0.932; P<.01) between the new sutural bone formation and amount of sutural separation. Piezoelectric sutural ostectomies increased the rate of sutural separation and promoted new sutural bone formation/osteogenesis. Continuous ostectomy gave better results than discontinuous ostectomy.